Step 1

Preheat oven to 350°F. In a small bowl microwave unsweetened chocolate 1 to 2 minutes or until melted, stirring every 30 seconds. Cool slightly.

Step 2

Coat a 10-inch fluted tube pan with nonstick baking spray. Add cocoa powder. Shake and tilt pan to coat interior; discard excess cocoa powder. In a medium bowl stir together flour, milk powder, baking soda, and 1/2 tsp. salt.

Step 3

In a large bowl beat butter with a mixer on medium to high 30 seconds. Add 1 cup of the granulated sugar, the brown sugar, and 1/3 cup vegetable oil. Beat until combined, scraping sides of bowl as needed. Add eggs, one at a time, beating until combined after each. Beat in melted chocolate and 1 1/2 tsp. of the vanilla.

Step 4

Alternately add flour mixture and 1 cup water to mixture, beating on low after each addition just until combined. Stir in chocolate chips. Pour batter into pan, spreading evenly.

Step 5

Bake 45 minutes or until a wooden skewer comes out clean. Cool in pan on a wire rack 15 minutes. Remove cake from pan; cool completely.

Step 6

For marshmallow meringue: In a large bowl beat the egg whites and cream of tartar with a mixer on medium until soft peaks form (tips curl). In a small heavy saucepan combine the remaining 1/2 cup granulated sugar, the light-color corn syrup, and 1/4 cup water; bring to boiling, swirling pan gently to dissolve sugar. Cook sugar syrup to 240°F (2 to 3 minutes), then immediately remove from heat. With mixer running on medium-low, slowly pour syrup in a steady stream into bowl with egg whites. Increase speed to medium-high and beat 4 minutes or until glossy and stiff. Beat in the remaining 1 tsp. vanilla and a pinch of salt.

Step 7

Once cake is completely cool, top with spoonfuls of marshmallow meringue. If desired, use a kitchen torch to lightly toast marshmallow meringue. Serves