This caramel apple cake is the epitome of fall - an impossibly moist spice cake, sun-ripened apples, nutty brown butter frosting and a rich swirl of caramel.
In a bowl, whip the eggs, brown sugar and granulated sugar on high until light and fluffy (2-3 minutes).
Combine the dry ingredients in one bowl and the wet ingredients in another.
Starting with the dry ingredients and alternating between wet and dry, add your ingredients to the egg/sugar mixture, whisking until just incorporated for each addition.
Pour the batter into a parchment paper lined 8"x8" square cake pan.
Layer the apple slices on top of the batter.
Bake at 350F for 40-45 minutes.
In a small pan, cook the butter on low-medium until it browns.
Pour into a bowl and allow to cool to room temperature.
Add the powdered sugar to the browned butter and beat on high until smooth.
If the frosting is too thick, add 2-3 tablespoons of milk to the frosting to thin it out.
Spoon the frosting onto the top of the cooled cake and spread into an even layer.
Drizzle caramel sauce over the frosting and swirl.
Notes
Testing for doneness: Although tempting to wait until the toothpick comes out completely clean, doing so will likely lead to over-baking your cake. Instead, you want your toothpick to come out without any raw batter and with some cooked crumbs still clinging to it.
Doneness of browned butter: You know your butter is adequately browned when it develops brown flecks and a nutty smell.
Salvaging overcooked browned butter: Should you overcook your butter, you can pour it through a strainer to remove the burned flecks.
Storage: This cake can be kept in an air tight container in the refrigerator and is best when eaten within 2-3 days.
Making this cake for a crowd: If you need more cake, simply double the recipe and bake it in a 9″x13″ at 350F adding 5-15 minutes to the bake time.