Combine 1 cup quinoa, 1 cup brown rice, almond milk, honey, brown sugar, and salt in a pot over medium heat; stir until almond milk is heated through, about 5 minutes.
Whisk egg in a small bowl. Mix in some of the hot milk mixture to gradually warm up the egg to room temperature.
Pour egg mixture into the saucepan. Add remaining 1/2 cup quinoa, 1/2 cup brown rice, vanilla extract, and pumpkin pie spice. Bring to a boil; reduce heat and simmer until mixture begins to thicken, 10 to 15 minutes. Scoop mixture into 2 serving bowls.