1. Prepare the cupcakes. Preheat oven to 350 degrees F. Line a 12-cup muffin pan with cupcake liners.
2. In a medium bowl, stir together flour, baking soda, baking powder, and salt.
3. In a large bowl, using an electric mixer on high speed, cream butter and sugar until light and fluffy, about 3 minutes. Add eggs, one at a time, mixing thoroughly after each addition. Beat in vanilla. Beat mixture on medium-high speed for 2 more minutes.
4. Add half the flour mixture and beat on low just until incorporated. Add buttermilk and blend until smooth. Add remaining flour and beat just until incorporated.
5. Fill each muffin cup with batter about 3/4 full. Bake until surface is pale gold and firm to the touch, about 15 to 18 minutes; a toothpick inserted in center of cupcake should come out clean. Let cool in pan for 5 minutes, then transfer to a wire rack to cool completely, about 20 minutes.
6. When cupcakes are cool, prepare topping. Heat cream in a medium saucepan over medium heat just until it begins to simmer; do not let it boil. Remove from heat and immediately add bittersweet chocolate, vanilla, and salt. Let sit 1 to 2 minutes so the hot cream can melt the chocolate. Whisk until smooth. Set aside.
7. Add white chocolate and butter to a medium microwave-safe bowl and heat on high 30 seconds until chocolate begins to melt. Stir until smooth. If necessary, heat for 15 seconds more. Transfer to a resealable plastic freezer bag. Seal bag and snip one corner of the bag with scissors, about 1/16 inch.
8. Dip cooled cupcakes in bittersweet chocolate glaze. Place on cooling rack until glaze sets.
9. One at a time, pipe white chocolate on top of bittersweet chocolate glaze, starting in the center of the cupcake and drawing a continuous swirl out to the outer edge. Then use a toothpick to draw webbed spokes starting at the center of the cupcake and drawing the toothpick to the outer edge, creating a spider web design. Let cool until glaze is set, then serve.
Source: Hannaford fresh Magazine, September - October 2014