Rhubarb-Sour Cream Snack Cake with Walnut Streusel

Preheat oven to 375 degrees Fahrenheit.

Combine rhubarb and 2 tablespoons of flour in a medium bowl; toss well to coat.

Place brown sugar and butter in a large bowl; beat with a mixer at medium speed until light and fluffy.

Add eggs, one at a time, beating well after each addition.

Add sour cream, orange rind, and vanilla; beat until well combined.

Lightly spoon all-purpose flour and whole wheat flour into the bowl.

Add baking soda, cinnamon, and salt, stirring with a whisk.

Gradually add flour mixture to butter mixture, beating at low speed just until combined.

Fold in rhubarb mixture.

Spread batter into a 9 inch square baking pan coated with cooking spray.

Combine sugar and cinnamon in a small bowl.

Cut in butter until mixture is crumbly; stir in nuts.

Sprinkle streusel evenly over batter.