Here’s a step-by-step guide to creating these delightful cupcakes.

Set your oven to 350°F (175°C). This step is crucial for ensuring even baking.

Line your muffin tin with cupcake liners. This will not only make for easy cleanup but will also give your cupcakes an aesthetically pleasing look.

In a large bowl, combine the flour, baking powder, baking soda, and salt. Whisk them together to ensure they are well mixed. This prevents clumping and ensures an even rise.

In another bowl, whisk together the melted butter, sour cream, and egg whites. Add the warmed milk, vanilla extract, and almond extract (if using). Mix until smooth, ensuring there are no lumps.

Gradually add the dry ingredients into the wet mixture. Stir gently until combined. Be cautious not to overmix. A few small lumps are perfectly fine.

Spoon the batter into the prepared cupcake liners, filling each about two-thirds full. This allows enough room for the cupcakes to rise without overflowing.

Place the muffin tin in your preheated oven and bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean.

Once baked, remove the tin from the oven and let the cupcakes cool in the pan for 5 minutes. Then transfer them to a wire rack to cool completely.

While the cupcakes cool, make the buttercream. In a mixing bowl, beat the softened butter until creamy. Gradually add the sifted powdered sugar. Incorporate the heavy cream and vanilla extract, mixing until you have a smooth, fluffy consistency. Adjust the consistency with milk if needed.

Once the cupcakes are completely cool, generously frost each with the vanilla buttercream. You can use a piping bag for decorative swirls or simply spread it on with a knife.

Sprinkle with rainbow sprinkles, lemon zest, or chocolate shavings for a personal touch.