Ingredients  (yields  20 standard muffins)

• 2 cups all-purpose flour
• 3/4 cup granulated sugar
• 2-1/2 tsp. baking powder
• 1 tsp. ground cinnamon
• 1/2 tsp. baking soda
• 1/2 tsp. kosher salt
• 1 cup sour cream
• 4 oz. unsalted butter, melted and cooled slightly
• 2 large eggs
• 1 tsp. pure vanilla extract
• 1-1/2 cups 1/4-inch-diced rhubarb

For the topping:

• 3 Tbs. brown sugar
• 1/2 tsp. ground cinnamon
• 1/8 tsp. nutmeg

Directions

In a large mixing bowl, combine the flour, sugar, baking powder, cinnamon, baking soda, and salt and whisk to blend.

In a medium bowl, whisk together the sour cream, melted butter, eggs, and vanilla until smooth. Lightly stir the sour cream mixture into the dry ingredients with a spatula until the batter just comes together; do not over mix. Gently stir in the diced rhubarb. The batter will be thick.  Scoop muffin mix into prepared baking cups or muffin tins and top with 1/4 tsp topping, sprinkling evenly.

Bake at 400 degrees until muffins are golden brown, spring back most of the way when gently pressed, and a pick inserted in the center comes out clean, about 18 to 22 minutes.