Preheat oven to 350 degrees and line pan with cupcake liners.
Sift cake mix into a small bowl and set aside.
In a large bowl, gently whisk egg whites, egg, oil, buttermilk, sour cream and vanilla.
Stir cake mix into wet ingredients.
Using half of the batter, fill cupcake liners about 1/3 full.
With the remaining cake batter, add the strong coffee and mix. Add 1 or 2 tablespoons of flour to thicken the batter.
Scoop the coffee cake batter over the regular batter so that each cupcake liner is filled about 3/4. Take a toothpick and gently swirl the coffee layer into the vanilla layer being careful not to mix, but instead marble.
Bake for 16-20 minutes or until an inserted knife comes out clean. Allow to cool completely.
Filling: Combine all ingredients in a small bowl using a spoon.
Topping: Using a whisk attachment on your stand mixer, beat cream cheese and powdered sugar until smooth. Add vanilla. Slowly add in heavy cream and beat until stiff peaks form.
To assemble, scoop a small piece of cake out the top of each cupcake (I use an apple corer to grab a tiny piece from the center). Generously spoon in your filling, icing any overage across the top of the cupcake. Pipe your whipped topping over the hole with the filling and top with chocolate shavings, cocoa powder, and/or a chocolate covered espresso bean.