Preheat your oven to 375°F (190°C) and grease a 9x13-inch baking dish.
In a large mixing bowl, whisk together the flour, sugar, baking powder, and salt.
In another bowl, combine the milk, melted butter, egg, and vanilla extract.
Pour the wet ingredients into the dry ingredients and stir until just combined.
Fold in the cooked sausage, cheddar cheese, and green onions if using.
Scoop the dough by the tablespoon into the prepared baking dish, spacing them evenly.
Bake for 20-25 minutes, or until the rolls are golden brown on top.
Let the rolls cool for a few minutes before serving.