Creating these delicious Brown Butter Apple Blondies is simple when you follow these steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C) and line a 9×13-inch baking dish with parchment paper, leaving some overhang for easy removal.
2. Brown the Butter: In a medium saucepan, melt the butter over medium heat. Continue cooking until it turns golden brown and smells nutty. Remove from heat and let it cool slightly.
3. Mix the Sugar and Eggs: In a large mixing bowl, combine the brown sugar and browned butter. Stir well. Add the eggs and vanilla extract, mixing until well combined.
4. Combine Dry Ingredients: In a separate bowl, whisk together the flour, baking powder, salt, and cinnamon. Gradually add this mixture to the wet ingredients, stirring until just blended.
5. Add Apples and Nuts: Gently fold in the diced apples and nuts (if using) until evenly distributed in the batter.
6. Bake the Blondies: Pour the batter into the prepared baking dish and spread it evenly. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
7. Prepare the Glaze: While the blondies are baking, prepare the cinnamon maple glaze. In a small bowl, mix powdered sugar, maple syrup, milk, and ground cinnamon until smooth and drizzle-able. Adjust the milk for desired consistency.
8. Cool and Glaze: Once baked, remove the blondies from the oven and let them cool in the baking dish for about 10-15 minutes. Then, lift them out using the parchment overhang and place on a wire rack. Drizzle with the cinnamon maple glaze before serving.