Peanut Butter Chocolate Chip Zucchini Cake

1/3 cup creamy peanut butter

1/4 cup butter, softened

1 cup packed brown sugar

1-1/2 cups all-purpose flour, divided

1/2 teaspoon salt

1/2 teaspoon baking soda

1 large egg, room temperature

1 teaspoon vanilla extract

1/4 cup buttermilk

1 cup shredded zucchini

1/4 teaspoon ground cinnamon

1/2 cup semisweet chocolate chips

Preheat oven to 350°. In a large bowl, cream peanut butter, butter and brown sugar until blended. In another bowl, whisk 1-1/4 cups flour, salt and baking soda; add to creamed mixture. Beat just until mixture is sandy. Remove 1/2 cup crumb mixture for topping. To remaining mixture, beat in remaining flour, egg, vanilla and buttermilk. Stir in zucchini. Spread into a greased 9-in. round baking pan. Stir cinnamon into reserved topping. Sprinkle over batter; top with chocolate chips. Bake until a toothpick inserted in center comes out with moist crumbs, 20-25 minutes. Cool in pan on a wire rack.