Preheat the oven to 350 degrees Fahrenheit. Line a 12-cup muffin tin with paper liners. Set it aside.

In a medium-sized bowl, thoroughly combine all-purpose flour, espresso powder, ground cinnamon, and salt.

In a large mixing bowl, use a hand mixer to cream together unsalted butter, granulated sugar, and light brown sugar until the mixture becomes fluffy.

Gradually add eggs, one at a time, along with vanilla extract. Mix until just combined. Then, incorporate sour cream into the mixture with a quick mix.

Add half of the dry flour mixture to the butter mixture and mix until fully incorporated. Pour in the remaining flour mixture and add whole milk. Mix until the ingredients come together to form a smooth batter.

Using a cookie scoop or a quarter-measure cup, fill each muffin liner about three-quarters full of the batter. Repeat this process until all the muffin liners are filled.

Place the muffin tray in the preheated oven and bake for 18 to 22 minutes, or until the cupcakes turn golden brown and a toothpick inserted comes out clean.

Allow the cupcakes to rest in the muffin tray for 5 minutes, then transfer them to a wire rack to cool completely.

In a large mixing bowl, use a hand mixer to cream the butter at medium speed for approximately 3 to 5 minutes until it becomes pale and fluffy. Gradually add powdered sugar, a few teaspoons at a time, while continuing to mix. Incorporate espresso powder, vanilla extract, and salt into the mixture. Slowly add heavy cream to achieve a smooth and fluffy frosting consistency.

Fill a piping bag fitted with a star-tip nozzle with the prepared frosting. Secure the other end of the piping bag with a small clamp to prevent leakage.

Swirl the frosting over the cooled coffee cupcakes and lightly dust them with cocoa powder. Enjoy!