Preheat oven to 350°F. Line a 9x13 dish with parchment paper.

In a small saucepan over medium heat, melt the butter, whisking constantly. Bring the butter to a simmer and continue whisking until the butter goes from yellow to golden brown and smells a little nutty. Pour the browned butter into the bowl of a stand mixer fitted with the paddle attachment and let cool for five minutes.

Cream together the butter and brown sugar until well combined.

Beat in the eggs and vanilla.

In a medium bowl, combine the baking powder, salt, 1 teaspoon cinnamon, nutmeg, and flour.

Slowly add the dry ingredients to the brown sugar mixture and mix until just combined.

Spread batter into the prepared pan.

In a small bowl, combine the sugar and remaining cinnamon. Sprinkle evenly over the top of the batter.

Bake for 20-25 minutes or until set. Cool completely before cutting and serving.