Preheat your oven to 350 degrees. Lightly grease a 9x13 baking pan and line with parchment paper.
Add all 3 ingredients to a large bowl
Mix ingredients together using a spatula or whisk. Mix just until no lumps remain
Use a spatula to spread the batter into the prepared pan, creating an even layer
Bake in preheated oven for 35 minutes
Carefully remove from oven and allow to cool in the pan completely