Preheat the oven to 400°F (200°C). Grease a 9x13-inch baking pan and set aside.
Combine the cornmeal and milk in a medium bowl. Let the mixture stand for at least 10 minutes so the cornmeal softens.
In a large mixing bowl, whisk together the flour, baking powder, salt, and sugar (or leave out sugar if using honey).
Using an electric mixer, beat in the eggs and coconut oil until the mixture is crumbly.
Add the milk and cornmeal mixture to the dry mixture and beat just until combined, about 30 seconds; do not overmix.
Fold in the cooked quinoa with a spatula, breaking up any lumps, until evenly distributed.
Pour the batter into the prepared pan and smooth the top. Bake for about 35 minutes, or until a toothpick inserted into the center comes out clean.
Let the cornbread rest for at least 5 minutes before cutting and serving while warm.
