Rhubarb Muffins are a delicious springtime and summer treat for breakfast and brunch. Topped with buttery cinnamon streusel, these muffins are soft, tender, and utterly habit-forming!
Preheat the oven to 425 degrees F. Grease a 12 cup muffin pan or line with paper cups.
In a medium bowl, combine the flour, baking soda, baking powder, and salt. Reserve 1 teaspoon of flour to toss with chopped rhubarb. In a separate bowl, whisk the brown sugar, oil, egg, vanilla, milk, and yogurt until smooth. Fold in the flour mixture, followed by the rhubarb, dusted in flour, just until combined. Spoon the batter into the prepared cups, filling almost to the top.
In a small bowl, stir together the melted butter, white sugar, and cinnamon; sprinkle the mixture on top of each muffin.
Bake for 5 minutes at 425°F then reduce the oven temperature to 350°F and bake until a toothpick inserted in the middle comes out mostly clean; about 18 to 20 minutes more. Or until the tops of the muffins spring back when lightly pressed. Cool in the pan for 10 minutes before serving.