Preheat the Oven: Begin by preheating your oven to 350°F (180°C). Line your muffin tin with cupcake liners and set it aside.
Prepare Dry Ingredients: In a medium bowl, sift together the all-purpose flour, baking powder, and salt. This step ensures your muffins have a uniform texture. Set the dry mixture aside.
Cream the Butter and Sugar: In a standing mixer fitted with the paddle attachment, beat together the melted butter and granulated sugar on medium speed. Continue mixing until the mixture becomes light and fluffy, which should take about 3 minutes. Be sure to scrape down the sides and bottom of the bowl as needed.
Incorporate Eggs and Vanilla: With the mixer still running on medium speed, add the eggs one at a time, ensuring each egg is well incorporated before adding the next. Then, add the pure vanilla extract and mix until combined.
Combine Dry Ingredients and Milk: Reduce the mixer’s speed to low and add half of the dry ingredients to the butter-sugar mixture. Mix just until combined. Then, pour in the whole milk and mix until incorporated. Finally, add the remaining half of the dry ingredients and gently mix, either on low speed or by hand. Avoid over-mixing; this will result in lighter, fluffier muffins.
Fill the Muffin Cups: Divide the batter evenly between the prepared muffin cups, filling each about 3/4 full.
Bake to Perfection: Bake for 15–20 minutes, or 8–10 minutes if making mini cupcakes. To check for doneness, insert a toothpick into the center of a muffin; it should come out clean or with just a few moist crumbs.
Cool and Enjoy: Allow the muffins to cool in the pan for about 10 minutes, then remove them and let them cool completely on a wire rack.
