PREHEAT & PREP. To start, preheat the oven to 350 degrees F. and line a ceramic or glass 9x9 baking pan with parchment paper.
COMBINE DRY INGREDIENTS. In a large bowl, combine gluten-free flour, gluten-free cornmeal, baking powder, baking soda & salt. Whisk until evenly blended.
ADD THE WET INGREDIENTS. Make a small well in the center of the dry ingredients, then add the milk, maple syrup, melted butter, and eggs. Stir or whisk until just combined. (A few lumps are fine!)
BAKE. Pour cornbread batter into your prepared pan and gently smooth the surface or shake the pan a bit to settle the batter into an even layer. Bake 15-20 minutes, or until a toothpick inserted in the center of the pan comes out clean with just a few moist crumbs. Brush with glaze while the cornbread is still hot.
WHILE THE CORNBREAD BAKES, MAKE THE GLAZE. In a small bowl, whisk melted butter with maple syrup. Brush glaze over the top of the cornbread when it’s hot from the oven. (It’ll feel like a LOT of glaze, but it will absorb into the bread without making it soggy!)
SERVE & STORE. Allow the cornbread to cool at least 15-20 minutes on a wire rack before slicing, for best results. Store leftover cornbread in an airtight container at room temperature 1-2 days, or in the fridge 2-3 days.