With just the added sugar from blueberries, these muffins are as nearly sugar-free as they come. They’re extra tender, moist, and coated in a buttery, sweet, cinnamon-y topping for a treat that’s equally suitable for breakfast, snack, or dessert.
Place a rack in the middle of the oven and preheat the oven to 350°F.
Lightly grease 8 wells of a standard muffin tin, or line them with muffin papers and lightly grease the papers; this will ensure that they peel off the muffins nicely.
To make the muffins: In a medium bowl, combine the flour, baking sugar alternative, baking powder, nutmeg, and salt. Set aside.
In a separate mixing bowl, combine the melted butter, vegetable oil, egg, milk, and vanilla, whisking until smooth.
Add the dry ingredients to the wet ingredients, stirring until combined. Fold in the blueberries.
Divide the batter evenly among the prepared muffin cups.
Bake the muffins for 20 to 24 minutes, or until they're a pale golden brown and feel set on top.
Remove the muffins from the oven and let them cool for a couple of minutes, or until you can handle them. While they're cooling, prepare the topping.
To prepare the topping: Put the melted butter into a small bowl and combine the baking sugar alternative and cinnamon in a separate small bowl.
Transfer the muffins to a cooling rack. Dip the top of each muffin into the melted butter. Return them to the rack for a minute or so before dipping in the topping to finish.
Serve the muffins warm, or cool on a rack and wrap airtight. Store for several days at room temperature; freeze for longer storage.
