Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking pan or line it with parchment paper.

In a bowl, whisk together flour, baking powder, cinnamon, and salt.

In a separate bowl, cream the softened butter with granulated and brown sugars until light and fluffy.

Add eggs one at a time and mix in vanilla extract until fully combined.

Gradually fold the dry ingredients into the wet mixture until just combined.

Pour the batter into the prepared pan, smoothing the top evenly.

Bake for about 20-25 minutes or until golden brown and slightly underbaked in the center.