Rhubarb Nut Streusel Cake

1 1/2 cups granulated sugar, divided
3 cups diced fresh rhubarb
1 tablespoon vinegar
3/4 cup butter
1/2 teaspoon baking soda
1 egg, beaten
3/4 cup milk
2 1/4 cups all-purpose flour
1/2 teaspoon baking powder
1/2 cup finely chopped nuts

Butter a 9-inch springform pan. Preheat oven to 350 degrees F.

Combine 3/4 cup sugar and cornstarch in medium sauce. Stir in rhubarb. Cook and stir over medium heat until mixture comes to a boil and thickens. Cool and set aside.

Stir together milk and vinegar; set aside.

Combine flour and remaining 3/4 cup sugar. Cut in butter until mixture is crumbly and set 1/2 cup of mixture aside.

To remainder add baking powder, baking soda and nuts. Combine egg and milk mixture and add to dry ingredients, stir until just moistened. Spread 2/3 of the batter over the bottom and sides of prepared springform pan. Spoon rhubarb filling over batter. Drop remaining batter over rhubarb by spoonful, sprinkle with reserved streusel mixture. Bake for 50 minutes.