Rhubarb Crumb Muffins are slightly dense with a nice thick buttery brown sugar crumble topping that stays crispy on top with a slight burst of sour rhubarb coming through in each bite.
Preheat oven to 350 degrees. Line a 12 cup muffin pan with paper liners.
In a large saucepan over medium heat, melt the butter and brown sugar, stirring to combine. Stir in the diced rhubarb and bring it to a slow simmer, remove from heat and let cool for 15 minutes.
Once rhubarb mixture has cooled, whisk in eggs.
In a medium bowl, combine flour, baking powder, cinnamon, salt and lime zest. Add dry ingredients to wet ingredients, stirring until just combined. Stir in lime juice.
Divide batter evenly between prepared muffin cups and set aside.
For the Crumble topping
In a small bowl, stir together melted butter, flour, brown sugar, almonds, cinnamon, and salt with a fork until crumbly.
Sprinkle topping over batter filled cups, pressing topping into batter.
Bake muffins for 20 minutes, or until a wooden pick inserted in center comes out clean. Cool muffins in pan on a wire rack for 5 minutes. Remove baked muffins from muffin pan and cool completely on wire rack.
To make the glaze (optional)
In a small bowl, whisk confectioners sugar and lime juice together until smooth. Drizzle over muffins.