A brown sugar, cinnamon, and nutmeg mixture makes an irresistible crumbly topping for this jumbo blueberry muffin recipe.
Heat oven to 350°F. Coat the 6 wells of a jumbo muffin pan with nonstick cooking spray. Prepare Crumb Topping: In a medium-size bowl, whisk together flour, light-brown sugar, cinnamon, nutmeg and salt. Work in butter with your fingertips until crumbs are formed. Set aside until batter is mixed and in the muffin pan.
In a small bowl, whisk together flour, granulated sugar, baking powder, baking soda and salt. Set aside. In a large bowl, whisk together 1/4 cup water, the eggs and oil. Stir flour mixture into oil mixture just until moistened. Gently fold in berries.
Divide batter among prepared wells, about 2/3 cup in each. Top batter with crumb topping, dividing equally (about 1/4 cup on each).
Bake at 350°F for 33 to 35 minutes. Cool in pans for 10 minutes, then transfer directly to wire rack and continue to cool. Before serving, dust with confectioners sugar, if desired.