Toffee Coffee Cake

1/2 cup butter, softened
1 cup packed brown sugar
1/2 cup sugar
2 cups all-purpose flour
1 teaspoon baking soda
1 cup buttermilk
1 egg, lightly beaten
1 teaspoon vanilla extract 3 chocolate English toffee candy bars (1.4 ounces each), chopped
1/4 cup chopped pecans

In a large mixing bowl, cream butter and sugars until light and fluffy. Beat in flour; set aside 1/2 cup. To the remaining butter mixture, beat in baking soda. Beat in the buttermilk, egg and vanilla; mix well. Pour into a greased 13-in. x 9-in. baking pan. Combine chopped candy and pecans with the reserved butter mixture; sprinkle over coffee cake. Bake at 350° for 30-35 minutes or until a toothpick inserted near the center comes out clean. Cool on a wire rack. Yield: 16 servings.