01 -
Heat your oven to 350°F (175°C) and grease a 9×13-inch baking pan so the bars won't stick.
02 -
In a large bowl, stir together the cake mix, eggs, oil, and vanilla until everything's well combined and smooth.
03 -
Gently fold in the chocolate chips and colorful sprinkles - don't overmix or you'll break the sprinkles and lose those pops of color!
04 -
Spread the thick batter evenly into your greased pan. It might be a bit sticky, so you can use a spatula with a bit of oil on it to help smooth the top.
05 -
Pop it in the oven for 20-25 minutes until the top is nice and golden brown. You'll know it's done when the edges start to pull away from the sides slightly.
06 -
Let the bars cool completely in the pan before cutting into squares. This helps them set up properly and makes for cleaner slices.