01 -
Using a hand mixer, cream together the softened butter and sugar in a large bowl until light and fluffy.
02 -
Add eggs, milk, and vanilla extract to the creamed mixture while continuing to mix until fully combined.
03 -
In a separate bowl, whisk together flour, baking powder, and salt to remove lumps and ensure even distribution.
04 -
Gradually add the dry ingredients to the wet ingredients in increments of 1/4 cup, mixing gently and scraping the bowl sides as needed to avoid flour dust.
05 -
Gently fold the rainbow sprinkles into the batter with a spatula until evenly dispersed without overmixing.
06 -
Preheat the oven to 350°F (177°C). Line a 12-cup muffin pan with paper liners and lightly spray each liner with nonstick baking spray.
07 -
Spoon batter into each liner, filling approximately three-quarters full. Optionally, sprinkle extra jimmies on top for decoration.
08 -
Bake in the preheated oven for 23 to 25 minutes, or until a toothpick inserted into the center emerges clean and free of wet batter.
09 -
Allow muffins to cool in the pan for 10 minutes before transferring them to a wire rack to cool completely. Serve with chilled milk if desired.