Rainbow Cupcakes

Preheat the oven to 350 degrees F (175 degrees C). Line two 12-cup muffin pans with paper baking cups.

Stir together flour, baking powder, baking soda, and salt in a large bowl. Whisk together milk, vegetable oil, and vanilla in a separate bowl until evenly blended; set aside.

Beat sugar and butter with an electric mixer in a large bowl until light and fluffy. The mixture should be noticeably lighter in color. Add eggs one at a time, allowing each egg to blend into the butter mixture before adding the next. Pour in the flour mixture alternately with the milk mixture, mixing until just incorporated.

Divide cake batter into four separate bowls. Add a few drops of food coloring into one bowl of batter and stir; add more food coloring if necessary to reach the desired shade. Repeat with remaining colors and bowls of batter.

Using a different spoon for each color batter, spoon a small portion of each color into the cupcake liners, until 1/2 to 3/4 full. Do not mix the batter once it is in the cupcake liner.

Bake in the preheated oven until a toothpick inserted into a cupcake comes clean, 15 to 20 minutes.