Set your oven to 350°F (175°C). Grease a 9x13-inch pan or line it with parchment paper for easy removal later.

In a large mixing bowl, combine the cake mix, eggs, vegetable oil, and vanilla extract. Stir until a soft, thick dough forms. It may be slightly sticky—that's okay.

Gently fold in the Easter M&Ms and chocolate chips until evenly distributed. The dough will be colorful and textured.

Spread the dough into the prepared baking dish. Press it evenly across the bottom using a spatula or your fingertips.

Bake for 20–25 minutes, or until the edges turn golden brown and the center is set. The top should look slightly puffed but not jiggly.

Remove the pan from the oven and let the bars cool completely. Once cooled, slice into 16 even squares.