Preheat the oven to 325°F. Line a standard 9x5-inch loaf pan with a sheet of parchment paper and lightly grease the pan and paper.

Melt the butter in a small saucepan over medium heat. Once melted, lower the heat to medium-low and cook, swirling the pan often, until the butter is deeply golden brown with dark speckles, about 6 minutes.

Take the browned butter off the heat and let it rest for 5 minutes, just until it is warm but not hot.

In a large mixing bowl, whisk together the cooled brown butter, eggs, pumpkin puree, vanilla, yogurt, and maple syrup until the mixture is completely smooth and uniform.

Add the gluten-free flour, cinnamon, coconut sugar, and baking soda to the wet mixture. Stir with a spatula or spoon just until the batter is smooth and no dry streaks remain; do not overmix.

Pour the batter into the prepared loaf pan and spread the top into an even layer.

Bake on the middle rack for about 60 minutes, until a small knife inserted in the center comes out just barely dry or with a few moist crumbs attached.

Let the bread cool in the pan for 10 minutes. While it cools, make the maple glaze by whisking the powdered sugar, maple syrup, and 1 teaspoon of milk in a small bowl; add more milk if needed to reach a drizzling consistency.

Use the parchment to lift the bread out onto a wire rack. Slice the warm or cooled bread and drizzle generously with the maple glaze before serving.