Make Rhubarb Muffins with tangy rhubarb and crisp streusel for bright, tender muffins everyone will love.
Preheat the oven to 400°F and prepare your muffin tin by greasing the twelve wells or lining them with paper liners. This is the simple first move that sets the bake up for success — have the tin ready and the liners arranged so you can portion batter without fuss.
In a large bowl whisk together the all-purpose flour, granulated sugar, baking powder, and salt until evenly combined and airy. Make sure there are no lumps — the dry mix should look pale, slightly aerated, and faintly powdery.
In a separate small bowl whisk the egg until smooth, then add milk, vanilla Greek yogurt, melted butter (or oil), and vanilla extract. Whisk until homogenous and slightly glossy; the wet mix should be fluid but creamy, with the yogurt lending a faintly thicker, satiny texture.
Toss the chopped rhubarb into the dry flour mixture so the bright pink-red pieces are coated and distributed, then make a shallow well in the center of the dry mix and pour the wet ingredients into it. Stir gently just until moistened — the batter should be thick, loosely cohesive, with visible streaks and pockets of rhubarb and a few streaks of flour remaining. Avoid overmixing to keep the muffins tender.

Divide the batter evenly across the twelve prepared wells, filling each to about two-thirds full. If using streusel, sprinkle a generous, even layer over each muffin so the tops will crisp and glisten when baked.
Bake for 16–19 minutes or until a toothpick inserted into the center comes out clean. Remove the muffins from the pan and cool completely on a baking rack so the crumb sets and the streusel crisps. Serve warm or at room temperature — a single muffin presented in its paper liner on a small plate with a scattering of fresh rhubarb pieces makes for a lovely finish.
