Ingredients
Equipment
Method
Prepare oven and pan
- Preheat the oven to 375°F and grease an 8x8-inch baking pan so the cake releases cleanly.
Mix dry and wet ingredients
- Whisk together all-purpose flour, sugar, baking powder, and salt in a large bowl until evenly combined and no dry pockets remain.
- In a separate bowl, mix butter, melted, egg, milk, and vanilla extract until combined and smooth.
Combine batter
- Pour the wet ingredients into the dry ingredients and stir until just combined, avoiding overmixing for a tender crumb.
- Fold in diced fresh rhubarb until the pieces are evenly distributed through the batter.
Bake
- Spread the batter into the prepared pan and sprinkle with cinnamon sugar topping for a golden, lightly sweet surface.
- Bake for 30-35 minutes at 375°F until golden and a toothpick comes out clean in the center.
Cool and slice
- Cool the cake for 10 minutes before slicing so the crumb sets and the rhubarb stays intact.
Notes
Pro tip: aim for “just combined” mixing after adding the wet ingredients—overstirring toughens the crumb. Store covered in the refrigerator up to 3 days and rewarm individual slices in the microwave for 15-20 seconds. Freezing yes: freeze slices wrapped airtight up to 2 months and thaw overnight in the fridge. For a dairy-light option, use plant-based butter and lactose-free milk in the same amounts.