Preheat oven to 400°F (204°C) and grease a 13x9-inch baking dish.

Cook and crumble the gluten-free sausage in a skillet until no longer pink, then drain grease. Stir in onion powder and ground sage.

Spread sausage mixture, hash browns, and cheddar cheese evenly in the prepared baking dish.

In a separate bowl, whisk eggs, gluten-free Bisquick, brown sugar, pepper, and milk until smooth. Pour over the sausage mixture.

Bake for 35-40 minutes, or until golden brown and set.