Step 1

Preheat oven to 325°F degrees and position rack in the center. Butter and flour a mini Bundt pan.

Step 2

Pour bourbon into a small bowl. Scrape seeds from vanilla bean into bourbon; stir to blend well (reserve scraped vanilla bean for another use like infusing sugar).

Step 3

Whisk flour, cornstarch, baking powder, baking soda and salt in medium bowl to blend.

Step 4

Using an electric mixer, beat butter, sour cream and sugar in large bowl until light and fluffy.

Step 5

Add eggs and egg yolk to the butter mixture one at a time, beating until well blended after each addition. Beat in bourbon-vanilla mixture.

Step 6

Add dry mixture in 2 additions alternating with milk in 1 addition, beating just until blended after each addition.

Step 7

Split batter in half.

Step 8

Add cocoa powder and milk to second batter and mix until incorporated.

Step 9

Add the first layer of vanilla batter to mini bundt pan; Add a layer of cocoa batter. Add the last layer of vanilla. Mix together to create a marbled look.

Step 10

Bake mini bundts for 20-25 minutes until tester inserted near center comes out clean.

Step 11

Cool in pan on rack 10 minutes. Invert bundts onto rack and cool completely.

Step 12

Melt over low heat, stir in cream. Mix together.

Step 13

Transfer to a piping bag.

Step 14

Mix together confectioners sugar and milk.

Step 15

Drizzle both glazes onto cooled mini bundts.