Instructions

• Preheat the oven to 350°F (175°C). Line 12–16 standard muffin cups with paper liners.
• Make the streusel: In a small bowl combine 3/4 cup all-purpose flour, 1/2 cup packed brown sugar, and 2 teaspoons cinnamon. Add the 6 tablespoons cold butter (cubed or grated) and cut or rub it into the dry ingredients with a pastry cutter, fork, or your fingers until the mixture is crumbly. Set the streusel aside in the refrigerator while you make the batter.
• In a large mixing bowl whisk together the wet ingredients: 1/2 cup salted butter (melted), 1/2 cup real maple syrup, 2 teaspoons vanilla extract, 1/2 cup buttermilk, 1/2 cup plain Greek yogurt, and 2 large eggs. Whisk until smooth and combined.
• Add the dry ingredients to the wet mixture: 2 cups all-purpose flour, 2 1/2 teaspoons baking powder, 1/2 teaspoon baking soda, 1/2 teaspoon cinnamon, and 1/2 teaspoon kosher salt. Stir gently until just combined and no large streaks of flour remain—do not overmix.
• Gently fold 1 1/2 cups fresh or frozen blueberries into the batter, keeping the batter light and lumpy.
• Divide the batter evenly among the prepared muffin cups, filling each about two-thirds full.
• Spoon the 1/3 cup high-quality blueberry jam over the filled muffin cups, dividing the jam between the muffins (a little in the center of each). Use a toothpick or skewer to gently swirl the jam through the top of the batter in each cup to create a blueberry swirl—avoid overmixing.
• Evenly sprinkle the chilled streusel over the tops of the muffins.
• Bake at 350°F for 25–30 minutes, or until a toothpick inserted into the center of a muffin comes out clean or with a few moist crumbs. If baking multiple pans, rotate them halfway through baking for even browning.
• Remove the muffins from the oven and let them cool in the pan for 5–10 minutes. Transfer the muffins to a wire rack to cool slightly. Serve warm or at room temperature.