Step 1

Preheat the oven to 425°℉. Line a 12-cup standard muffin pan with muffin liners or spray with baking spray.

Step 2

Wash the rhubarb and trim the ends. Cut the rhubarb into ¼ inch dice. Set aside.

Step 3

In a medium bowl, whisk together the flour, baking soda, salt, and cinnamon. Set aside.

Step 4

In another bowl, whisk together the sugar and eggs until well blended. Add the sour cream, milk, melted butter, vanilla, and orange zest and stir until combined. Then add the wet ingredients to the flour mixture. Stir until the flour is fully incorporated. Fold in the rhubarb. Do not over-mix. The batter will be somewhat thick.

Step 5

Scoop the batter into the prepared muffin pan, evenly distributing the batter. Top with turbinado sugar or other coarse sugar.

Step 6

Bake at 425°℉ for 7 minutes. After 7 minutes, decrease the oven temperature to 350°℉ and bake for another 12-15 minutes until the tops are golden, and a toothpick inserted in the center comes out clean.

Step 7

Allow the muffins to cool for 10 minutes in the pan. After 10 minutes, remove to a wire rack to finish cooling. Serve warm or at room temperature.