📖 Instructions

1. Preheat your oven to 350°F (175°C). Line a 12-cup muffin tin with cupcake liners. Don't skip this step or your cupcakes will stick to the pan. Trust me on this one--I learned the hard way!
2. In a large mixing bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside. I sometimes accidentally forget this step, and its a nightmare trying to mix everything in later, so don't be like me!
3. In a separate large bowl, cream together the butter and both sugars until light and fluffy. This is where a good electric mixer comes in handy. Beat it until you're happy.
4. Beat in the eggs one at a time, then stir in the vanilla. Make sure to scrape down the sides of the bowl to ensure everything is well combined.
5. In a small bowl, whisk together the milk and the melted butter. Make sure the butter is fully melted or it'll be a weird, lumpy batter.
6. Gradually add the dry ingredients to the wet ingredients, alternating with the milk mixture, beginning and ending with the dry ingredients. Mix until just combined. Don't overmix!
7. In a separate small bowl, make your cake batter swirl. Add 1 cup of the batter to the bowl. Add a tablespoon of sprinkles (optional) and beat until the sprinkles are evenly distributed.
8. Spoon the batter into the cupcake liners, filling each about 2/3 full. Then, spoon about a tablespoon or two of the cake batter swirl batter into the center of each cupcake liner. Use a toothpick to gently swirl the batters together, creating a marble effect.
9. Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean. Keep a close eye on them – ovens vary, and you don’t want burnt cupcakes. If you want perfectly round swirls, use a piping bag to get a really pretty effect.
10. Let the cupcakes cool in the muffin tin for a few minutes before transferring them to a wire rack to cool completely. This is important! Otherwise you will have a crumbly mess to clean up
11. Once the cupcakes are completely cool, you can frost them with your favorite frosting. I personally love a classic cream cheese frosting, but the sky is the limit! Get creative and have fun with it!