Preheat the oven to 375 degrees F. Spray three 8-inch round cake pans with non-stick spray and line them with parchment. Spray again and set aside.

In a medium bowl, whisk together the melted butter and coffee granules until dissolved. Stir in the graham cracker crumbs and sugar until the crumbs are damp.

Divide the mixture evenly between the three pans and press down firmly to form a crust. Bake for 6-8 minutes until golden brown. Let cool.

Preheat the oven to 325 degrees F for the cake.

In an electric mixer bowl, combine flour, sugar, cocoa, baking soda, baking powder, and salt. Mix on low speed until combined.

In another bowl, combine buttermilk, oil, eggs, water, and vanilla.

With the mixer on low speed, slowly add the wet ingredients to the dry, scraping the bottom of the bowl.

Pour the batter into the pans over the crust (about 16 ounces in each pan) and bake for 25-30 minutes or until a toothpick comes out with a few moist crumbs.

Cool in the pans for 15 minutes, then turn out onto a cooling rack and cool completely. Wrap in plastic wrap and chill until ready to use.

For the cheesecake filling, beat cream cheese and sugar until smooth, about 2 minutes. Set aside.

In a chilled bowl, beat heavy whipping cream until stiff peaks form. Fold into the cream cheese mixture, then fold in toffee pieces and chocolate chips. Store in the refrigerator until ready to use.

For the caramel, mix sugar, water, and corn syrup in a saucepan. Bring to a boil over medium heat without stirring until it caramelizes to a golden brown color.

Remove from heat and slowly mix in heavy cream little by little. Mix in salt and vanilla. Let cool to room temperature before using.

For the buttercream, in an electric mixer, beat the butter on medium-high for 3-5 minutes. Gradually add powdered sugar, then increase speed and beat until light and fluffy for another 5 minutes.

Turn the mixer to medium and gradually add the caramel. Mix on medium-high until incorporated.

To assemble, spread a dollop of buttercream on a cake board. Place the first cake layer, crust side down, on the cake board. Pipe a rim of buttercream around the edge and fill with half of the cheesecake filling.

Repeat for the second layer. Place the final layer, crust side down, on the second layer of filling.

Apply a thin layer of buttercream around the cake as a crumb coat. Freeze the cake for 10-15 minutes to set.

Once set, frost the cake with remaining buttercream.