INGREDIENTS
1 cup
unsalted butter, softened
1 3/4 cups
granulated sugar
2
lemons, zested
3
eggs
1 tsp
pure vanilla extract
2 1/2 cups
+ 2 tbsp all-purpose flour, divided
1 tsp
baking powder
1 tsp
Kosher salt
3/4 cup
buttermilk
3 cups
rhubarb, diced in 1/2-inch pieces
2 cups
icing sugar
1
lemon, juiced
1 tbsp
melted unsalted butter