Step 1

Preheat oven to 350 degrees and spray a 9x9 pan with cooking spray or coat with butter.

Step 2

In a large bowl, mix melted butter and brown sugar. Add in the eggs and vanilla and whisk vigorously until smooth.

Step 3

Add the flour, baking powder, and salt and stir until well incorporated.

Step 4

Pour the batter into the prepared pan and smooth out.

Step 5

Place in the oven to bake for 30 minutes until edges are golden and toothpick comes out mostly clean.

Step 6

Allow to cool completely, then cut into squares.