Grease 18 muffin tins and preheat oven to 375.
In a large mixing bowl, combine the flour, baking powder, sugar, salt and sage. Add the oil and the eggs, then pour in the milk and whisk together.
Stir in the diced red bell pepper and cooked sausage.
Fill the greased muffin tins 2/3 full with batter.
Bake muffins in the preheated oven for 20-24 minutes, or until cooked through.
Let cool on cooling rack before serving.
To Freeze: Let cool completely before adding to a plastic freezer baggie or container.
To Thaw: Let sit on the counter for a bit, or reheat in the microwave on the defrost setting.