1-First, preheat your oven to 350°F (175°C) and line a cupcake tray with paper liners. Prepare all ingredients by measuring precisely to avoid any surprises in the baking process. This step sets the stage for success and helps everything come together smoothly.

2-Next, in a large mixing bowl, sift together the flour, baking powder, and salt to ensure even distribution. This creates a light base for your cupcakes, which is crucial for that fluffy texture we all love.

3-In a separate bowl, cream the softened butter and sugar until light and fluffy. Gradually add the egg and egg white, mixing well after each addition, followed by the vanilla extract. This builds the flavor and moisture into the batter.

4-Alternate adding the flour mixture and milk to the butter mixture, beginning and ending with flour, and mix gently to avoid over-beating. Once combined, fill each cupcake liner halfway with batter, add a teaspoon of dulce de leche in the center, and cover with more batter.

5-Bake for 18-22 minutes or until a toothpick inserted near the center comes out clean, but avoid piercing the dulce de leche center. Allow the cupcakes to cool in the tray for 10 minutes, then transfer to a wire rack. For even better results, consider tips from experts, like those in this external guide on 10 tips for baking cupcakes.