1. Preheat the oven to the temperature indicated on your brownie mix box or your homemade brownie recipe (usually between 325-350°F or 165-175°C).
2. Grease a 9×13-inch baking pan with butter or non-stick spray to ensure easy brownie removal.
3. Gather all ingredients — brownie mix, honey, brown sugar, cinnamon, butter, milk, eggs, vanilla extract, and icing sugar if using a glaze.
4. In a mixing bowl, combine brownie mix with cinnamon and brown sugar, stirring until evenly mixed.
5. Melt the butter in a separate bowl and let it cool slightly.
6. Whisk the wet ingredients, including eggs, honey, vanilla extract, milk, and melted butter, until fully combined.
7. Gradually mix the wet ingredients into the dry brownie mixture, stirring until the batter is smooth and consistent.
8. Pour the batter into the greased baking pan, spreading it evenly with a spatula.
9. Place the pan in the preheated oven and bake according to the brownie mix instructions or until a toothpick comes out clean.
10. Remove from the oven and cool the brownies in the pan on a wire rack.
11. If desired, prepare an optional glaze by mixing icing sugar with a little milk until it reaches your preferred drizzling consistency.
12. Once the brownies are completely cooled, drizzle the glaze over the top for extra sweetness.
13. Slice the brownies into your desired size and serve.
14. Store any leftovers in an airtight container at room temperature for up to a week or in the freezer for longer storage.