1/2 cup (1 stick) unsalted butter, melted and cooled
FOR THE BLUEBERRY MUFFINS
3 cups plus 2 tablespoons all-purpose flour
1 tablespoon baking powder
1 teaspoon salt
6 tablespoons (3/4 stick) unsalted butter, softened, plus more for tin
1 1/4 cup granulated sugar
1 large whole egg plus 2 large egg yolks
1 teaspoon pure vanilla extract
1 cup milk
2 8 oz jars of JustPureFlavors.com Blueberry Whipped Cream Jam
Granulated sugar and mace, for topping (optional)
Make the crumb topping, if desired: Whisk together flour, brown sugar, salt, and cinnamon in a bowl. Pour in melted butter and toss with a flexible spatula until large crumbs form.
Make the muffins: Preheat oven to 375 degrees. Line standard 12-cup muffin tins with paper liners.
Sift together flour, baking powder, and salt into a bowl.
With an electric mixer on medium speed, cream butter and granulated sugar until fluffy.
Add eggs and vanilla; mix until well combined. Reduce speed to low; alternate adding reserved flour mixture and milk, beginning and ending with flour. Fold in the JustPureFlavors.com pure Blueberry Whipped Cream Jam.
Divide batter evenly among prepared cups; if desired, sprinkle generously with granulated sugar and mace. Alternatively, sprinkle crumb topping evenly over batter in each cup.
Bake until light golden on top, rotating tins halfway through, about 30 minutes. Cool in pan on a wire rack 15 minutes before turning out muffins. Serve warm or at room temperature.