Preheat your oven to 350°F (175°C). Grease a 9x13 inch baking dish with butter or non-stick spray, then set it aside.
In a large mixing bowl, whisk together the flour, sugar, baking powder, salt, ground cinnamon, and ground nutmeg until well combined.
In another bowl, beat the eggs and then add the milk, melted butter, maple syrup, and vanilla extract. Whisk until thoroughly combined.
Pour the wet ingredients into the dry ingredients and mix until just combined. Avoid over-mixing to ensure a fluffy texture.
Pour the batter into the prepared baking dish and smooth the top with a spatula.
Bake in the preheated oven for 20-25 minutes, or until a toothpick inserted in the center comes out clean. Remove from the oven and let it cool completely in the pan.
In a small bowl, whisk together the powdered sugar and 2-3 tablespoons of milk until smooth to make the glaze. Adjust the consistency as needed.
Once the donut bars are cool, cut them into rectangular bars. Dip the tops in the glaze or drizzle it over the bars using a spoon.
For an extra touch, drizzle some additional maple syrup on top of the glazed bars before serving.
Notes
For an extra touch, drizzle some additional maple syrup on top before serving.