The first step is to make the cinnamon mixture. In a bowl add melted butter, brown sugar, ground cinnamon, and 2 tablespoons of all-purpose flour. Mix until well combined and set aside.
Preheat the oven to 350 degrees Fahrenheit and grease a 9×5-inch loaf pan. Set aside.
In a separate large bowl, add the eggs, granulated sugar, and vanilla extract, and whisk to combine. Then, add the sifted all-purpose flour, almond flour, baking powder, and melted butter. Whisk until combined.
Pour half of the cake batter into your prepared baking pan Add the cinnamon mixture on top, then pour the remaining batter over it. Use a table knife or toothpick to swirl it into the batter. I topped it with some chopped pecans however this is optional.
Bake for 45-50 minutes in a preheated oven. Let cool before serving. Enjoy!