Preheat the oven to 350°F. Grease and line a 9-inch spring form pan with parchment paper. In a large mixing bowl, cream the brown sugar and melted butter until smooth.
8 tablespoons unsalted butter, ¾ cup brown sugar
Pour in the eggs one by one into the batter, mixing until completely combined and smooth. Add the vanilla extract and almond extract, and combine again. Make sure everything is completely incorporated.
4 large eggs , 2 teaspoons vanilla extract, 1 teaspoon almond extract
In a separate bowl, whisk together the almond flour, all purpose flour, cinnamon, baking powder, and kosher salt, and make sure there are no lumps or clumps.
2 cups almond flour finely ground, ½ cup + 2 tablespoons all purpose flour, 1 tablespoon cinnamon, 1 teaspoon baking powder, 1 teaspoon kosher salt
Combine the wet and dry ingredients. Mix gently until everything is incorporated, scraping the sides of the bowl with a rubber spatula to ensure everything gets in the mixture. Be careful not to overmix.
Add the cake batter to the greased and prepared cake tin and use a rubber spatula to spread out the batter evenly. We also like to bang the pan on the counter a few times to bring air bubbles to the surface before baking.
Bake for 35-40 minutes, until the edges of the cake are golden brown and beginning to pull away from the pan. The cake should spring back a little bit when touched, and a toothpick inserted into the center should come out with a few moist crumbs still attached. Set aside to cool.