Rhubarb Crumb Bars

Martha Stewart
Makes 16 squares

For the streusel:
6 tablespoons unsalted butter, melted, plus softened butter for pan
1 cup flour, plus more for pan
1/2 cup packed brown sugar
1/4 teaspoon salt

For the cake:
1/2 pound rhubarb, cut into 1/2 inch pieces
1 tablespoon brown sugar
1 cup flour
1/2 teaspoon baking powder
1/4 teaspoon salt
1/2 cup unsalted butter, room temperature
1 cup icing sugar
2 large eggs
1/2 teaspoon vanilla

Preheat oven to 350F. Butter an 8 inch square baking pan. Line with parchment leaving an overhang on two sides. Butter and flour parchment and pan, tapping out excess flour.

Make the streusel by whisking butter, brown sugar and salt. Add flour and stir with fork till large crumbs form. Refrigerate til ready to use.

In a medium bowl, combine rhubarb, brown sugar and 1/4 cup flour. In another medium bowl, whisk 3/4 cup flour, baking powder and salt. In a large bowl using an electric mixer, beat butter and icing sugar until light and fluffy. Beat in eggs, one at a time. With mixer on low, beat in vanilla then flour mixture. Spread batter in prepared pan. Sprinkle with rhubarb and top with streusel.

Bake til golden and toothpick inserted in center comes out with moist crumbs attached, about 45-50 minutes. Let cool completely in pan. Using paper overhang, lift out cake and cut into 16 bars.