Preheat the oven to 350 degrees
Grease an 8x8 baking pan or line with parchment paper
Whisk together the flour, baking soda, baking powder, and salt in a large mixing bowl
Combine the brown sugar, eggs, melted butter, and vanilla with the hand mixer. Do not overmix
Pour the wet ingredients into the bowl with the dry ingredients and mix
Remove 1/3 cup of batter for each color you are using. Place each portion into an invidivual smaller bowl.
Drop 3-4 drops of food coloring into each of the smaller bowls and mix with a fork until evenly combined
Distribute the confetti chips into each bowl of batter.
Spoon each of the colored batter portions into the baking dish, combining the colors and plain batter in a pattern
Swirl the colors together until they are combined to create a rainbow or unicorn effect
Top with sprinkles
Bake for approximately 25 minutes or until cooked through