Preheat oven to 350°F. Spray 3 (8-inch round) cake pans with baker’s spray and set aside.

In a medium mixing bowl, sift together the cake flour, unsweetened cocoa powder, baking powder, baking soda, and salt.

In a separate, large mixing bowl, whisk together the granulated sugar, eggs, whole milk, canola oil, and vanilla extract.

Add the dry ingredients to the bowl of the wet ingredients and whisk until fully combined.

To the very hot water, add the instant coffee granules, stir to dissolve the coffee into the water, then add to the batter. Whisk until you have a smooth chocolate cake batter.

Evenly divide the batter between the three prepared cake pans. You can use a kitchen scale to ensure that each of the pans are approximately the same weight.

Bake the chocolate cakes for 20-25 minutes or until a toothpick inserted comes out clean. Allow the cakes to cool in the pans for 10 minutes before transferring them to a wire rack to cool completely before frosting them.

In the bowl of a stand mixer fitted with a paddle attachment, beat the unsalted butter on medium speed until light and fluffy with no lumps. Add the creamy peanut butter and beat again until fully combined and smooth.

Add the sifted powdered sugar and mix until all the powdered sugar is fully incorporated. You will need to start on low speed and build your way up to medium-high speed. You may need to stop and scrape down the sides and bottom of your bowl when making your frosting to ensure that all the ingredients are evenly incorporated.

Add the heavy cream and vanilla extract and mix again for 2-3 minutes or until your peanut butter frosting is smooth and fluffy. You want your frosting to be slightly on the thick side yet still spreadable. You can add a little extra powdered sugar to the frosting, starting with ½ cup at a time, to thicken the frosting if it is too thin. If it is too thick, you can add extra heavy cream, starting with 1 tablespoon at a time. Be sure to stop and scrape down the sides and bottom of the bowl with each addition to ensure your frosting is evenly mixed.

Remove 1 cup of the peanut butter frosting and place it into a large piping bag fitted with a decorative piping tip to pipe the decorative dollops around the edge of the cake once fully frosted.

Add one cooled cake layer to a serving plate or cake stand. If your cake is slightly domed from baking, you can use a large serrated knife to carefully remove the domed portion to give you a flat, even cake layer. Add approximately 1 cup of the peanut butter frosting to the top of the first cake layer and spread evenly from edge to edge with an offset spatula. Add the second cake layer, followed by more frosting, then the third cake layer. Add the remaining peanut butter frosting to the top and sides of the cake. Be sure that your frosting is evenly spread over the top and sides of your cake.

Add the chopped semi-sweet chocolate bar, heavy cream, and unsalted butter to a medium-sized microwave-safe bowl. Microwave on high for 1 minute. Allow the warmed cream and chocolate to sit for 1 minute, then whisk to completely combine the ingredients into a smooth, silky ganache. Allow the ganache to cool slightly on the counter (but still at a pourable consistency) before adding to the cake.

Using a large spoon, carefully spoon the chocolate ganache onto the top of the cake, allowing it to drip down the sides. Carefully smooth the chocolate into an even layer covering the entire surface of the top and down the sides of the cake. You can use an offset spatula, or plastic bench scraper, to carefully spread the ganache into a thin, even coating on the entire surface area of the cake. Place the cake into the refrigerator to firm up the ganache layer for a minimum of 1 hour before piping the decorative dollops of peanut butter frosting around the top edge of the cake. You can add the optional Reese’s Pieces candies for garnish.