Whisk multigrain flour, quinoa flour, sugar, baking powder, and salt together in a large bowl. Mash coconut oil with a fork in a bowl; whisk into flour mixture until well mixed. Measure 1 cup mixture, reserving the rest in a large container with a lid in the refrigerator for another use.

Mix the 1 cup flour-coconut oil mixture, milk, and egg together in a bowl until batter is well mixed.

Heat a lightly oiled griddle over medium-high heat. Drop batter by large spoonfuls onto the griddle and cook until bubbles form and the edges are dry, 3 to 4 minutes. Flip and cook until browned on the other side, 2 to 3 minutes. Repeat with remaining batter.