Start by peeling and dicing 2 medium apples into small pieces, about a ½” or smaller. Set them aside.

Next, brown the butter. Because you’ll be browning butter for both the maple apple blondies and the maple icing, brown all of it at the same time. Cook 1 cup unsalted butter over medium to medium-low heat in a light-colored skillet or stainless-steel pan, stirring constantly for 5-8 minutes. Once browned, set aside in a heatproof container. For more detailed information, read “How to Brown Butter” in the post.

Add the apples to the same pan you browned the butter in and add 2 tablespoons of maple syrup and a ½ teaspoon ground cinnamon. Cook over medium heat, stirring occasionally, until softened and cooked down slightly. This should only take about 5 minutes or so. Set the pan aside while you make the batter.

Preheat your oven to 350°F / 180°C. Prepare a 13x9 baking pan by buttering the sides or spraying with non-stick spray. Line the long side with parchment paper that hangs over the side to create a sling. This makes removal and cutting easier later. Set it aside.

In a large mixing bowl, add 2 ⅓ cups all-purpose flour, 1 ½ teaspoons baking powder, ½ teaspoon salt, 1 teaspoon ground cinnamon, and a ¼ teaspoon ground nutmeg and whisk together. In another mixing bowl combine ¾ cup of the browned butter, ½ cup apple butter (if using), 1 ¼ cups packed brown sugar, 2 large eggs, and 1 teaspoon of vanilla extract. Whisk until fully combined.

Pour the wet mixture into the larger mixing bowl with the dry ingredients. Whisk until just combined, then add the apples and any juices remaining in the pan. Fold together gently and immediately add the batter to the prepared 13x9 baking pan.

Spread the batter as evenly as possible throughout the pan. Place into the oven and cook for 30-40 minutes. The top should be lightly browned, and a toothpick or cake tester should come out mostly clean. Set it on a cooling rack and allow it to cool completely in the pan.

Once cooled, prepare the maple icing. By now the reserved ¼ cup of browned butter has probably resolidified, so microwave it for a few seconds until it liquifies again. In a small mixing bowl, combine the reserved browned butter, 1 cup powdered sugar, 2 tablespoons milk, 2 tablespoons maple syrup, ¼ teaspoon vanilla extract, and ½ teaspoon of ground cinnamon. Whisk until the icing is smooth and thick, but somewhat pourable. If it’s too thin, add more sugar, and if it’s too thick, add a bit more milk.

Using a spoon or squeeze bottle, drizzle the maple icing across the top of the cooled apple blondies. Remove from the pan and slice into squares for serving.