In a medium size mixing bowl, whisk the dry ingredients, all-purpose flour, baking powder, salt, and cinnamon. Set aside.
Use a stand mixer with paddles attached or a large mixing bowl with an electric hand mixer with beaters attached, cream together, unsalted butter, brown sugar, white sugar, eggs, and vanilla until well combined, about 5 minutes.
Gradually beat in the dry ingredients until a batter forms.
Fold in the apple mixture to combine the ingredients.
Spread the batter into the prepared baking dish and bake in the preheated oven for 25-30 minutes or until a toothpick comes out clean.
Allow the blondies to cool slightly while making the glaze.