Combine Strawberries, 1/3 cup sugar, water, and cornstarch in a small saucepan. Cook over low heat for 5 to 7 minutes, stirring constantly until the sauce is thick, and strawberries are soft and broken down. Set aside to cool.Crumble Topping
Combine all of the topping ingredients in a bowl and rub together with your fingertips until crumbly. Set Aside
Preheat the oven to 350 degrees F
Grease and flour (or use Baking spray with flour) a square pan that is at least 8x8. You could use 9x9 or 10X10.
Cream together the Butter and sugar until light and fluffy.
￼￼￼￼￼￼Add eggs 1 at a time, beating well after each addition. Add vanilla.
Sift together dry ingredients. Add the dry ingredients to the creamed butter in 3 parts alternating with the sour cream in 2 parts. You will want to start and end with the flour. Beat just until combined.
You will spoon 2/3 of the batter into the prepared pan. Spread the cooled Strawberry mixture on the batter. It is easier to drop it by spoon.
Spoon the remaining batter onto the strawberries and spread evenly. Top with the streusel topping, and bake in the upper third of the oven. Bake for 50-60 minutes, or until a knife inserted in the center comes out clean!