Prep: Line a 9" springform pan with parchment paper on the bottom. Set aside.
Crush graham crackers: Place the graham crackers in a ziploc bag and whack them with a rolling pin until it become finely crushed crumbs. You can also use a food processor if you have one. Transfer the crumbs to a small mixing bowl.
Crumb mixture: Add the melted butter and stir together until all the crumbs are saturated and the mixture has the texture of wet sand.
Press into pan: Transfer the crumb mixture to your lined springform pan. Use the flat bottom of a cup or measuring cup to press the crumb mixture up the sides of the pan and into a flat layer on the bottom of the pan. Let the crust chill in the fridge while you prepare the filling.
Peanut Butter Cheesecake
Whip cream: In a medium mixing bowl, add the whipping cream. Use a whisk or an electric hand mixer to beat the cream until it becomes firm peaks. Set aside.
Cream cheese mixture: In a large mixing bowl, add the cream cheese, greek yogurt, powdered sugar, peanut butter, and vanilla extract. Use a hand mixer to beat the mixture on low speed, moving up to medium speed once it's mostly combined, until it's thick and creamy.
Combine: Add the whipped cream to the cream cheese mixture and fold together with a spatula until no streaks remain.
Fill crust: Transfer the mixture into your chilled crust. Use an offset spatula to smooth the top of the cheesecake filling. Cover and chill in the fridge overnight to allow the cheesecake to set.
Chocolate Ganache
Heat cream: Place the finely chopped chocolate in a small heat-safe bowl. In a small saucepan or in the microwave, heat the whipping cream on low heat just until small bubbles start coming to the surface and it barely begins to simmer.
Melt chocolate: Pour the hot cream over the chocolate and let it sit undisturbed for 3 minutes. Stir the mixture starting from the middle of the bowl until all the chocolate has melted and you have a smooth and shiny ganache.
Cool: Let the ganache cool until it has thickened to a thick but fluid, pourable consistency. Meanwhile, prepare the cheesecake and peanut butter in the next steps but keep an eye on the ganache. You don't want it to firm up completely and you'll need to work quickly once it reaches the desired pouring consistency.
Release cheesecake: Release your cheesecake from the springform pan and transfer to a serving dish or cake stand. Add some peanut butter to a small piping bag and snip off the top. Set aside.
Pour ganache: Pour the chocolate ganache on top of the cheesecake and use an offset spatula to spread it to the edges.
Marbled peanut butter design: Before the ganache sets, quickly pipe thin straight lines of peanut butter across the ganache. Drag a toothpick through the ganache, perpendicular to the peanut butter lines, to create a marbled design. Pop the cheesecake back into the fridge for about 15 minutes, just to let the ganache set.
Slice: Run a knife under hot water and wipe dry in between each cut when slicing the cheesecake for clean slices.