Step 1: Preheat your oven to 350°F (175°C) and line a 12-cup muffin tin with paper liners.
Step 2: In a large mixing bowl, whisk together the dry ingredients: flour, cocoa powder, baking powder, baking soda, and salt. Set aside.
Step 3: In a separate medium bowl, whisk together the wet ingredients: eggs, granulated sugar, vegetable oil, and vanilla extract. Gradually add the buttermilk, followed by the hot coffee or hot water, mixing until smooth.
Step 4: Pour the wet ingredients into the dry ingredients. Mix gently with a spatula or whisk until just combined. Be careful not to overmix, which can lead to tough cupcakes.
Step 5: Divide the batter evenly among the prepared cupcake liners, filling each about three-quarters full.
Step 6: Bake for 18 to 22 minutes, or until a toothpick inserted into the center of a cupcake comes out clean.
Step 7: Remove from the oven and let the cupcakes cool in the muffin tin for a few minutes before transferring them to a wire rack to cool completely. They must be completely cool before frosting!
Step 1: In a large bowl, using an electric mixer, beat the softened unsalted butter on medium speed until it's light and fluffy, about 2-3 minutes.
Step 2: Gradually add the powdered sugar, one cup at a time, mixing on low speed until combined, then increasing to medium until fluffy.
Step 3: Stir in the crushed freeze-dried strawberry powder, vanilla extract, heavy cream (start with 2 tablespoons and add more if needed for consistency), and a pinch of salt. Beat on medium-high speed until the frosting is smooth, creamy, and well combined.
Step 4: Once the cupcakes are completely cool, transfer the frosting to a piping bag fitted with your favorite tip, or simply use an offset spatula to spread it on top. Garnish as desired with fresh strawberries or chocolate.