This muffin batter can be prepared ahead of time and refrigerated overnight for use in the morning, making it the perfect “make ahead and prepare for breakfast” muffin.
Combine the streusel ingredients in a mixing bowl until crumbly. Set aside.
In a mixing bowl, mix together the dry ingredients. In a separate bowl, mix together the wet ingredients. Carefully add the wet ingredients to the dry. Mix only as much as necessary to fully incorporate. Gently fold in the blueberries. Divide evenly into a greased muffin tin. Top each muffin with the streusel mixture. Place the muffin tin into the convection steam oven on the wire rack set on position 2. Turn the oven on by selecting the Convection Humid Mode set to 350 °F. Bake until a toothpick inserted into the center comes out clean, approximately 20 minutes.