Let’s break down the process into easy-to-follow steps. I’ll guide you through each stage.

Step 1: Preheat and Prepare. Preheat your oven to 350°F (175°C). Line two muffin tins with cupcake liners.

Step 2: Cream Butter and Sugar. In a large bowl using a hand mixer (or in the bowl of a stand mixer), beat together the softened butter and granulated sugar until light and fluffy.

Step 3: Add Eggs and Vanilla. Add the eggs one at a time, beating well after each addition. Add the vanilla extract and mix until combined.

Step 4: Whisk Dry Ingredients. In another large bowl, whisk together the flour, cornstarch, baking powder, and salt.

Step 5: Combine Wet and Dry. Add half of the dry ingredients to the wet ingredients, beating until just combined. Pour in the milk and mix until fully incorporated. Add the remaining dry ingredients and stir until just combined. Be careful not to overmix.

Step 6: Bake. Fill the cupcake liners ¾ full with batter. Bake until slightly golden on top and a toothpick inserted into the middle comes out clean, about 25 minutes.

Step 7: Cool. Remove the cupcakes from the muffin tins and let them cool completely on a wire rack before frosting.

These instructions are very simple to follow.