Keto Peanut Butter Cup Cheesecake with Brownie Crust

 

So... A Reeses Peanut Butter Cup Cheesecake Tart! Keto-style! I was bored and out of sorts, my husband was grouchy and I was thinking of a way to cheer him up, dessert is always a great mood-enhancing palliative, so I pulled out an egg, a block of cream cheese, sour cream, butter etc from the fridge, let them come to room temperature, then I made the crust, baked it, let the crust cool, filled it with the peanut butter batter, baked it, let it cool in the oven with the oven door cracked, then removed the sides of the pan, placed the tart on a rack and stuck it in the fridge for a few hours, after which I completely smothered it in sugar-free chocolate ganache (which I make by melting sugar-free chocolate chips with coconut oil), let that harden for another hour and voila! I totally winged it... I had no intention of reliving the joy of my youth with this Reeses's Peanut Butter Cup meets Drake's Funny Bones mash-up, but once I started blending the cheesecake batter, I felt I needed something more than cream cheese and vanilla to stand up to the brownie crust... and then I remembered an unopened jar of peanut butter in the pantry and a star was born! It's a bit of a process... requires patience, but can easily be made a day ahead of whenever you wish to serve it. The tart is rich, decadent, not overly sweet and definitely satisfied my chocolate peanut butter cup jones. You cannot tell that this is a sugar-free, gluten-free dessert... it has all the flavor and mouthfeel of its sugary, starchy cousin.

A few notes: I use two types of Swerve for this tart. Swerve is made from ingredients found in select fruits and starchy root vegetables, and contains no artificial ingredients, preservatives or flavors. It’s zero-calorie, non-glycemic and safe for those living with diabetes, since it has no effect on blood glucose or insulin levels. Unlike other natural sweeteners like stevia, it has no bitter aftertaste and measures just like sugar. It's also the only sugar replacement of its kind that browns and caramelizes just like sugar. If you have Swerve but it's granulated instead of powdered, just blitz it in a coffee grinder first. If you are using other kinds of sugar substitutes I can't vouch for the amounts needed. I use Swerve because of its 1:1 ratio with cane sugar. I am bad at arithmetic and simply cannot be bothered calculating, so using a sweetener that not only tastes like real sugar but acts like real sugar and can be used in the same amounts as real sugar is a no-brainer. If you don't have brown sugar Swerve, that's okay... just sub in more powdered Swerve, though Lakanto golden monkfruit sweetener is something I have also used as a brown sugar substitute with success. 

I used Whole Food's 365 sugar-free dark chocolate chips brand sold on Amazon Whole Foods or Amazon Fresh for the crust and the ganache. Lily's is also a great brand, but it costs twice as much and the difference in taste and texture (both raw and cooked) is so negligible as to be non-existent. You can use blocks of sugar-free dark chocolate and grate them, but chips are absolutely perfect for melting and save you a step in what is already a multi-step process.

Ideally, all your ingredients should be room temperature, makes them easier to process and incorporate together. Most especially the cream cheese. Just take it out before you go to bed at night or as soon as you wake up in the morning and leave it on the kitchen counter. It'll be fine and ready for you when you need it later that day. 

When baking custards (which is what a cheesecake batter essentially is), it's always a good idea to humidify the oven to prevent the custard from cracking. Of course, in this case, since we are covering the custard with a chocolate coating, it won't matter if it cracks, but there is satisfaction in doing a thing well, and having a crevice-free cheesecake is always a minor miracle that uplifts the spirit, so.... put a pan of hot water on the lowest rack in your oven when you preheat the oven. This will add the much needed moisture without going through the trouble of setting up a bain-marie. 

A 9-inch non-stick removable bottom fluted tart pan like this one is ideal for this dessert and the bake time I suggest assumes it's the pan you're using. It's a kitchen essential, so buy one if you don't have one. You can find them easily online for a good price. If you must use a larger or smaller pan, adjust the cooking time accordingly. The fluted tart pan makes it look like a classic dessert, but if you haven't got one, you can line a pie plate with parchment paper and butter it instead.

Keto Peanut Butter Cup Cheesecake with Brownie Crust

For Brownie Crust

If you'd rather not make a pan of brownies for the crust, and are looking for something a bit less labor intensive, you can certainly take any leftover or store-bought sugar-free brownies, chocolate wafers or cookies and process them into crumbs, then add a bit of melted butter to them & press them in a pan, but making your own is worth the trouble. 

 

Ingredients:

 

• 3/4 stick butter (cut into small cubes) 
• 1/2 cup Swerve confectioners sugar (powdered)
• 1/3 cup Swerve brown sugar
• 1/2 cup sugar free dark chocolate chips 
• ½ cup walnuts, chopped 
• 4 Tbsp. almond flour 
• 2 tsp. unsweetened cocoa powder
• 2 large eggs, whites and yolk separated
• 2 Tbsp heavy whipping cream
• 1 tsp of vanilla extract
• salt (just a pinch for whipping egg whites) 

Instructions:

1. Preheat the oven to 350°F. 
2. Melt the dark chocolate chips with butter cubes gently in a microwaveable bowl using 30 second intervals to heat. Stir chocolate and butter between intervals (shouldn't take more than 3 intervals) 
3. Then whisk in 3 large egg yolks.
4. Whisk in the cream
5. Add both sugars, followed by the cocoa powder, both flours, mix very well... these sugar substitutes take a little longer to incorporate than cane sugar - and finally, add the chopped nuts.
6. Whip the egg whites in a stainless bowl with a pinch of salt until stiff peaks form, then add to the chocolate mixture folding in carefully with a rubber spatula so as not to deflate the whipped eggs.
7. Pour the batter into an 8″-square baking dish that's been lined with parchment paper (I use a Le Creuset stoneware baking dish with enamel interior, but any shape will do - we are going to blitz the brownies into crumbs anyway so it won't matter) and bake for 30 minutes. 
8. Remove from the oven and let cool.
9. Once cooled, cut into squares and add squares into a food processor, processing until crumbs form, add a tsp of vanilla, process more... if crumbs appear too dry add cream or milk & process again until dough is sticky.
10. Press crumbs out evenly into an 9 inch non-stick tart pan with a removable bottom. If you aren't sure whether your pan is non-stick, play it safe & spray it with avocado or coconut oil spray / or butter the pan with unsalted butter.
    
11. Bake crust in a preheated 350 F oven for 20 minutes. Then let cool and harden. While crust cools, make peanut butter cheesecake batter.
    
    

For Peanut Butter Cheesecake Batter: 

Ingredients

• 8 oz block of cream cheese, room temperature
• half a cup of sour cream, room temperature
• 1 medium egg, room temperature
• 1 tsp vanilla extract
• 3 Tablespoons of powdered Swerve
• 1/4 cup of natural crunchy peanut butter (no sugar, no additives - just peanuts & salt. Whole Foods makes a good one for a low cost), room temperature

Instructions

1. Preheat oven to 350 degrees. Add hot water to a roasting pan & place it on the lowest rack of the oven to provide needed humidity for the cheesecake. This prevents cracking.
2. Puree cream cheese in a food processor on high until soft and fluffy, stopping to scrape sides of bowl with flexible rubber spatula. Add the sour cream. Process until well incorporated with the cream cheese. Stopping to scrape bowl occasionally. Add powdered Swerve. Process until light and fluffy. Stopping to scrape bowl. Add peanut butter. Process. Scrape. Add vanilla. Process. Scrape, Then add egg. Do not over process egg... 30-45 seconds should suffice. Scrape sides of bowl. 
3. Pour filling into cooled brownie crust. Removing any bubbles you see on the surface. Let the batter rest for 5-10 minutes to allow any surface bubbles to subside.
4. Place aluminum foil on a cookie sheet. Place tart pan on the aluminum foil & lightly crimp around the bottom edges of pan to prevent the butter from the crust from leaking. Place cookie sheet with tart pan in center of the center rack of oven.
5. Bake undisturbed for 28 minutes. Center may still be a little jiggly.
6. Turn off oven, leave tart in oven with door cracked open for about 20 minutes to cool.
7. After 20 minutes, remove from oven, carefully separate the bottom of the tart from the sides, insuring that no part of the crust or custard are attached to the sides, place on wire rack to cool for an additional 30 minutes, then refrigerate on rack for two hours
8. After two hours, glaze the tart with chocolate ganache (recipe below), return to refrigerator for an additional hour or so to allow ganache to set.
9. When ganache is set, remove from oven garnish with berries. Slice, serve, and enjoy!

For Chocolate Ganache:

You can garnish this anyway you like. I kept it simple and just added whole strawberries after the ganache cooled, but if you'd like to incorporate chopped peanuts as a lovely border around the tart, you must add them immediately after glazing the tart with the ganache, while the ganache is still soft and warm, then refrigerate it for an hour until the chocolate sets again. You can, of course, use the microwave to melt the chocolate, but I prefer doing it directly in a small pan on a low burner, using a rubber spatula to mix as needed while it's melting. The coconut oil is an excellent emulsifier, don't skip it. 

Ingredients:

• 1/3 cup of sugar-free chocolate chips
• 1 Tbsp of coconut oil
• 1 Tbsp unsalted butter, room temperature
• 1 Tbsp heavy cream, room temperature
• Strawberries, chopped peanuts, anything you like as garnish (optional)

Instructions:

1. Add chips, oil, and butter into a small heavy-bottomed non-reactive sauce pan over low to medium low heat. Keeping an eye over it during the entire process, stirring together, to prevent chocolate from scorching as needed. Won't take more than a few minutes. 
2. When chocolate and fats are melted and well incorporated, remove from heat, add cream, gently stirring in until fully incorporated and emulsion is homogenous.
3. Place a sheet of aluminum foil on work surface where you intend to glaze the tart. Remove tart from refrigerator with wire rack, place on aluminum foil, get warm ganache ready to glaze. Use an offset spatula to glaze the tart, if you don't have one specifically designed for pastry, use a fish spatula... it offset & narrow enough... if you don't have that either? Spoon it on and swirl with back of the spoon, just be sure that you are smoothing it on evenly. 
4. If you want to add garnishes that will be embedded in the chocolate glaze, now is the time to add them, otherwise, just place tart on it rack with the foil beneath in the fridge to cool for an hour.
5. Cut and serve with berries, freshly whipped cream, anything you like. I prefer it plain with just a few raspberries or strawberries.