Preparation

• Start by browning the butter. Place all 20 tablespoons of unsalted butter in a light-colored skillet over medium heat. Stir constantly until the butter has turned a golden brown color, which will add a nutty flavor to your blondies. Pour 3 tablespoons of the browned butter into a small bowl for the icing, and set it aside while reserving the rest for the batter.
• In the same skillet, add the peeled and chopped apples along with either the pure maple syrup or brown sugar and the 1/8 teaspoon of ground cinnamon. Cook this mixture over medium heat until the apples soften, which should take about 3-5 minutes. Remove them from the heat and set aside.
• Preheat your oven to 350°F (177°C) while you prepare your baking pan. Line a 9x13 inch baking pan with parchment paper, ensuring some overhang for easy removal.
• In a large bowl, whisk together the all-purpose flour, baking powder, salt, the 1 teaspoon of ground cinnamon, and the 1/4 teaspoon of ground nutmeg.
• In another bowl, combine the reserved brown butter with the packed brown sugar, eggs, and the 1 and 1/2 teaspoons of pure vanilla extract. Whisk together until you achieve a smooth mixture.
• Pour this combination into the bowl with the dry ingredients and stir until just combined. Gently fold in the softened apples to ensure even distribution.
• Spread the batter evenly into the prepared baking pan. Bake in the preheated oven for approximately 35 minutes, or until the top is lightly browned and a toothpick inserted into the center comes out mostly clean.
• Allow the blondies to cool completely in the pan on a wire rack.
• To make the icing, whisk together the reserved brown butter, confectioners’ sugar, milk, vanilla extract, and a pinch of salt in a bowl. Adjust the consistency if necessary by adding more milk or sugar.
• Once the blondies are completely cooled, spread the icing over the top. Cut them into squares and store or enjoy.