Instructions

LEMON SUGAR TOPPING

1. Stir the sugar and lemon zest until combined and set aside.

MUFFINS

1. Adjust an oven rack to the upper-middle position and preheat your oven to 425 degrees. Line a 12 cup muffin pan with cupcake liners and set aside.
2. Bring 1 cup of blueberries and 1 teaspoon sugar to a simmer in a small saucepan over medium heat. Cook, mashing blueberries with a spoon several times stirring often to break down the berries. Cook until the mixture is thickened and reduced to 1/4 cup, about 10-12 minutes. Transfer the mixture to a bowl and let cool for about 15 minutes.
3. Whisk the flour, baking powder and salt together in a large bowl. Whisk 1 1/8 cups sugar and eggs together in a medium bowl until combined. Slowly whisk in the butter and oil until combined. Whisk in the buttermilk and vanilla extract until combined. Using a rubber spatula, fold the egg mixture and remaining 1 cup of blueberries into the flour mixture until just moistened. Do not over mix.
4. Using an ice cream scoop or a large spoon, divide batter evenly among your prepared muffin pan. Batter should completely fill the cups and mound slightly at the top. Spoon 1 teaspoon of the blueberry jam onto the center of each mound of batter. Using a skewer, gently swirl the blueberry jam into the batter using a figure-eight motion. Sprinkle the tops with the lemon sugar topping.
5. Bake until the muffins are golden brown and a toothpick inserted in the center comes out with a few moist crumbs attached, about 17 to 19 minutes, rotating the muffin pan halfway through baking. Let the muffins cool in the pan for 5 minutes, then transfer to a wire rack and let cool for 5 more minutes before serving.