Prepare the loaf pan. Preheat the oven to 350°F. Grease the loaf pan of your choice, Nordic Wheat Loaf Pan, an 8x4 inch or 9x5 inch loaf pan. Line the 8x4 and 9x5 inch loaf pans with parchment paper and set the pan aside. Whisk the dry ingredients. In a medium-sized bowl, whisk together the gluten-free flour, almond flour, baking powder, baking soda, salt, pumpkin pie spice, and cinnamon. Set the bowl aside.
Mix the wet ingredients. In a large mixing bowl or stand mixer with a whisk attachment, whisk together the sugar, dark brown sugar, pumpkin puree, and eggs until smooth. Add the melted oil, milk, vanilla extract, and lemon juice. Mix until combined.
Combine wet and dry ingredients. Add the dry ingredients to the wet ingredients, mixing until the flour is just incorporated. Avoid over-mixing.
Add batter to the pan. Pour the batter into the prepared loaf pan. Tap the pan on the counter a few times to release any air bubbles. (If using an 8x4 or 9x5 inch pan, run a knife about 1 inch deep lengthwise through the center of the loaf to encourage the bread to evenly dome.) Skip this step is using the Nordic pan.
Bake. If using the Nordic pan, place the pan on a baking sheet and into the oven for 45-50 minutes. (At the 45-minute mark check your loaf by inserting a toothpick in the center. If the toothpick comes out clean, the loaf is done baking.)
Transfer the bread to cool. Allow the bread to cool in the pan for 10 minutes then carefully transfer it to a wire rack to completely cool.