Preheat oven to 350°F and line regular or mini cupcake tins with cupcake liners. Using a stand mixer fitted with the paddle attachment (or a large mixing bowl with a hand mixer), combine the butter, sugar, egg whites and vanilla extract and beat on medium-low speed until creamy.
In a separate bowl, combine the flour, baking powder and salt. Mix well. Gradually add to the butter mixture and beat on medium-low speed until just combined. Add the sour cream and heavy cream and mix until just combined.
Fill each cupcake liner with batter (it will be thick and should nearly reach the top of the liner) and bake in the preheated oven for 14-16 minutes (9-11 min, if making mini cupcakes), or until a toothpick inserted into the centers come out clean. Let cool.
MAKE THE FROSTING
In a large bowl, mix (using whisk attachments) the butter with a hand-held or stand mixer on medium speed until fluffy. Add the peanut butter, confectioners’ sugar and heavy whipping cream and mix on medium speed for 1-2 minutes, or until frosting is smooth and spreadable.
ASSEMBLE THE CUPCAKES
Using a sharp knife cut a 1-inch chunk out of the top center of each cupcake. Spoon 1/2 teaspoon of the jelly into each hole. Spread or pipe the frosting over the tops. Drizzle the ice cream topping over the tops and serve!
Notes
Drizzling strawberry ice cream topping over the tops can be skipped, but I love the touch of color the topping adds to the outside of the cupcakes.
If you'll be serving these at a gathering, drizzle just before serving. Guests will be WOWed!
Don't throw away the bits of cupcake that you cut out of the centers. Use them to make Cupcake Truffles!
This recipe makes 18 regular-sized cupcakes or 44 mini cupcakes.