Preheat the oven to 350℉ and line a 12-cavity cupcake pan with parchment paper.
Whisk all dry ingredients together.1½ cups All-purpose flour, 1½ teaspoon Baking powder, ¼ teaspoon Salt
Use the paddle attachment to beat the room-temperature butter and sugar for 2 minutes until light, fluffy, and creamy.½ cup Butter, 1 cup Granulated sugar
Add in the oil and vanilla extract and mix well. 2 tablespoon Oil, 2 teaspoon Vanilla extract
Add in the egg whites and beat well. The mixture should look homogenous and light. 3 Egg whites
Switch to a spatula and add the dry ingredients, alternating with buttermilk. Start and finish with dry ingredients. Gently mix, and do not overmix. Fill the cupcake liners to ⅔ and bake them. Bake them for 15-18 minutes, and let them cool before frosting.½ cup Buttermilk
Espresso Soak
Mix the brewed coffee and dark rum in a small, shallow bowl. 1 cup Brewed coffee, ¼ cup Dark rum
How To Make The Mascarpone Cream
Beat the cold Mascarpone cheese, powdered sugar, and salt on low speed with the paddle attachment until smooth and creamy. 8 ounce Mascarpone cheese, 1 cup Powdered sugar, ¼ teaspoon Salt,
Add the cold whipping cream, vanilla extract, and yolk, turn the speed to medium-high, and beat the mixture until it thickens and becomes stable. The egg yolk bonds the cream ingredients and makes it more stable. The mascarpone cream should become pipeable and not too soft and runny. ¾ cup Heavy cream, 1 Yolk, 1 teaspoon Vanilla extract
Assembly
Let the cupcakes cool completely before frosting them. Use a Cupcake Corer or a small knife to make a hole inside the cupcakes. Dip a small piece of Lady Fingers Cookie (about 1.5 inches long) into the coffee/rum mixture and insert it into the cupcake cavity. Use a fork to poke the cupcake top so the coffee penetrates the cupcakes. 6 Lady Fingers Cookies
Pour one tablespoon of the coffee/rum mixture over the cupcakes.
You can use a different piping tip to pipe the Mascarpone cream on top of the cupcakes. Top the cream with cocoa powder dusting. The combination of cocoa powder and espresso flavour adds a unique mocha flavour to the cupcakes. Enjoy these decadent cupcakes with a cup of coffee :) 2 tablespoon Cocoa powder