"The cake has a delicate chocolate flavor, so it's not overpowering. I enjoy the special glaze the most. Although I wrote the recipe to say "cool completely," the cake tastes delicious served slightly warm about a half-hour after you have inverted it from the pan." —Barb Combs, Fort Collins, CO
1. To prepare glaze, combine first 4 ingredients in a small saucepan. Bring to a boil over medium-high heat, stirring constantly. Cool completely.
2. Preheat oven to 350°.
3. To prepare cake, drizzle oil into a 12-cup Bundt pan; coat pan thoroughly with a pastry brush. Sprinkle with 2 tablespoons flour, shaking out excess. Coat prepared pan with cooking spray.
4. Place 1 1/2 cups granulated sugar and 6 tablespoons butter in a large bowl; beat with a mixer at medium speed until well blended (about 5 minutes). Add eggs and egg whites, 1 at a time, beating well after each addition. Beat in vanilla.
5. Lightly spoon 3 cups flour into dry measuring cups; level with a knife. Combine 3 cups flour and next 4 ingredients (through salt), stirring with a whisk. Add flour mixture and milk alternately to sugar mixture, beginning and ending with flour mixture; mix after each addition. Beat 2 minutes. Fold in chips. Spoon batter into prepared pan. Swirl batter using a knife.
6. Bake at 350° for 45 minutes or until a wooden pick inserted in center comes out clean. Immediately pour glaze over cake. Cool cake in pan on a wire rack 30 minutes. Invert cake onto a serving plate; cool completely. Sprinkle with 2 tablespoons powdered sugar.