Heat oven to 350°F. Prepare two muffin pans with cupcake liners.
Stir together flour, cocoa, baking powder, baking soda, instant espresso powder and salt in large bowl.
In a second mixing bowl, whisk together the eggs, oil, sour cream (or greek yogurt), vanilla extract, and sugar .
Add the wet ingredients to the dry and stir just until combined. Do not overmix.
Fill each cupcake well about 3/4 cup full of batter.
Bake for about 14 minutes, rotating pans halfway through baking. Remove cupcakes from pans and allow to cool on a wire rack. Cool completely.
For the frosting combine the butter and powdered sugar and mix on low, then increase the speed for 2-3 minutes until light and fluffy. Add in your heavy cream, vanilla extract, and instant espresso powder. Beat on medium-high for 8 minutes.
With a pastry bag and tip attached, pipe the frosting on each cupcake. Decorate with sprinkles. Store at room temperature for up to 2 days. Refrigerate for up to 3 days, just bring back to room temperature before serving.