Preheat the oven to 350°F. Spray an 8×8-inch baking pan with nonstick spray and set aside.
In a small bowl, add one tablespoon of flour to the strawberries and rhubarb and gently stir to coat the fruit with the flour. Set aside.
In a medium bowl, whisk together 2 cups of flour, baking powder, and salt. Set aside.
In a large bowl, cream together the sugar, ¼ cup butter, and egg on medium-high speed with an electric mixer for 1 to 2 minutes. Add ½ cup milk and mix on low speed until smooth, 1 to 2 minutes.
Add the dry ingredients and stir just until mixed.
Gently stir in the flour-coated fruit.
Spread the mixture evenly into the prepared pan.
In a small bowl, mix together the topping ingredients of brown sugar, 3 tablespoons of flour, and 3 tablespoons of butter until it is crumbly. Sprinkle the crumb mixture on top of the cake batter.
Bake for 35 to 40 minutes or until the cake tester comes out with just a few crumbs on it. Let it sit in the pan for 10 minutes before serving.
For the glaze, whisk together in a small bowl the powdered sugar, 1 tablespoon of milk, and vanilla. Drizzle over the cooled cake.
Notes 
:
This cake pairs perfectly with a homemade pumpkin spice latte for brunch or with vanilla ice cream for dessert. The flour coating on the fruit helps prevent it from sinking to the bottom of the batter. 
For a variation, consider adding a pinch of cinnamon to the crumb topping for an extra flavor twist. 
