Step 1

In a small bowl combine first four ingredients - 1/2 cup sugar, 1/3 cup flour. cinnamon and butter - and mix together, using your fingers to push the sugar and flour into the butter to make coarse crumbs. Set aside

Step 2

Preheat oven to 350 and prepare a 9 inch spring-form pan with cooking spray. A 9" square baking pan will work as well.

Step 3

In a large mixing bowl combine 2 cups all purpose flour, 3/4 cup sugar, baking powder and salt. Whiisk to combine. Then add in milk and egg and fold until well combined and most powder bits are gone. Gently fold in rhubard. Pour batter into prepared pan, smoothing it out to reach the edges (or corners of the pan). Sprinkle top evenly with crumb topping. Bake at 350 for 45-50 minutes. Toothpick inserted into center of the cake should come out clean when the cake is ready. Edges will be lightly browned.

Step 4

Remove cake from oven and allow to cool 15-20 on a wire rack before removing from pan.

Step 5

Prepare glaze by combining powdered sugar, vanilla and I tablespoon hot water. Stir well, adding more water only to reach desired consistency. Glaze should be just thin enough to drizzle. Too thin and it will disappear as it settles on the cake. Using the a spoon, drizzle the glaze all over the top of the cake. Serve. Cake will keep for several days if covered and refrigerated.