In an electric mixer fit with paddle attachment, beat together butter and sugar until creamy and light. Add eggs, one at a time, mixing thoroughly between each addition.

Whisk together flour, baking powder, and salt.

Alternating with milk, add flour mixture to creamed butter/sugar mixture. Do not over-mix, just until incorporated.

Add in extract and stir well.

Divide evenly into 12 cupcake liners and bake at 350°F for 20 minutes or until toothpick inserted comes out clean.

In a medium-size saucepan, stir together water and corn syrup over medium heat.

Continue stirring until boiling (medium-high heat). Remove from heat.

Stir in powdered sugar with whisk, 1 cup at a time, until smooth and creamy without lumps.

Pour half of glaze into microwave-safe bowl.

Add chocolate to remaining half and stir until chocolate is melted and smooth.

Use an offset spatula to drizzle chocolate across center of cupcakes in a line. Fill in one side with chocolate glaze. Fill in other side with white glaze.

If glazes thicken, warm slightly in microwave or on stove-top.