• Preheat oven to 350. Spray a bundt cake pan with non-stick cooking spray and set aside.
• In a medium bowl, combine all-purpose flour, granulated sugar, unsweetened cocoa powder, baking powder and salt. Set aside.
• In a large bowl using an electric hand mixer, combine butter, egg yolk, egg whites, milk, instant coffee and vanilla extract.
• Gradually add dry ingredients to wet ingredients using an electric hand mixer low speed, scraping down the sides and bottom of the bowl periodically, until all flour mixture is incorporated.
• Turn hand mixer speed to medium and mix cake batter for to more minutes.
• Pour cake batter into prepared bundt pan coated with cooking spray.
• Bake for 35 minutes in preheated oven or until a wooden toothpick inserted near the center comes out clean.
• Let cake cool in pan on wire rack for 10 minutes, then remove cake from pan.

For the optional Peanut Butter Caramel Sauce

• If using the peanut butter caramel sauce, heat caramel in microwave 30 seconds, or until hot. Remove caramel from microwave and heat the peanut butter in a microwave safe bowl for 30 seconds. Add the hot caramel sauce to the melted peanut butter and stir to combine., drizzle cooled cake with Peanut Butter Caramel Drizzle