01 -
Preheat the oven to 400°F. Line a 12-cup muffin tin with paper or foil baking cups.
02 -
In a medium mixing bowl, combine the flours, granulated sugar, baking powder, cinnamon, baking soda, and kosher salt. Whisk to blend.
03 -
In a large bowl, whisk together the Greek yogurt, melted butter, eggs, and vanilla extract until smooth.
04 -
Add the dry ingredients to the wet ingredients and gently stir with a spatula until the batter just comes together; do not overmix. Gently fold in the diced rhubarb.
05 -
Evenly divide the batter among the muffin cups. The batter should mound slightly higher than the rim of the cups.
06 -
In a small bowl, mix the granulated sugar and ground cinnamon for the topping. Sprinkle about ½ teaspoon of the cinnamon-sugar mixture over each muffin. Pat gently onto the tops with your fingers.
07 -
Bake the muffins at 400°F for 20-22 minutes, or until golden brown and a toothpick inserted into the center of a muffin comes out clean.
08 -
Let the muffins cool in the pan for 5-10 minutes, then transfer them to a wire rack to cool completely. Best served warm.