Preheat oven to 350°F (or 325°F convection). Line or grease a 12-muffin tray with non-stick spray or paper liners.
In a large mixing bowl whisk the gluten free flour, baking powder, salt, and pepper.
In a separate bowl, mix the pumpkin, eggs, oil, and water. Add the pumpkin mixture to the dry ingredients, and mix until combined.
Gently fold in the sausage and sage.
Spoon about ¼ cup of the mixture into each muffin cup. Bake until the tops spring back when touched, 20 to 25 minutes.
Turn muffins out onto a rack to cool. Serve immediately. Muffins are best enjoyed freshly baked, but they may be refrigerated in an airtight container for up to 2 days. Reheat in the oven and serve warm.