Preheat the oven to 375 degrees. Prepare a muffin tin with nonstick cooking spray.

Whisk together the dry ingredients for the cake: almond flour, whey protein, instant espresso, baking powder, baking soda, and salt. Set aside.

In a mixing bowl, beat the butter, golden sweetener, and granulated sweetener until creamy, about 5 to 6 minutes.

To the butter mixture, add the eggs, vanilla, and greek yogurt. Blend until combined.

Add the dry ingredients and stir just until mixed.

Divide the batter between the wells of the muffin tin, filling them about 3⁄4 full.

Bake the cakes for 18 to 20 minutes or until the edges are golden and a toothpick inserted in the center returns clean.

Allow the cakes to cool completely in the muffin pan before removing them. Slice the tops off the muffins to create a flat top but reserve the tops for the final topping.

Stir together the hot water and instant espresso.

In a mixing bowl, beat the mascarpone cheese, erythritol sweetener, vanilla, and 2 tablespoons of the coffee soak.

In a separate bowl, beat the heavy cream until soft peaks form. Fold the heavy cream into the mascarpone mixture.

Place one cake into each of six jars. Spoon about 1 tablespoon of the soak over the cake.

Place a layer of the mascarpone cream over the cake. Top with an additional cake and then another scoop of the mascarpone cream.

Stir together the crumbled cake tops with the cocoa powder. Sprinkle over the tops of the jars.

Refrigerate overnight.