1. Preheat oven to 350°F (176°C) and line cupcake pan with cupcake liners.
2. Beat butter and sugar until light in color and fluffy, about 3-4 minutes.
3. Add eggs one at a time, beating just until blended.
4. Add vanilla, water and cocoa powder to another bowl and whisk until smooth. Mixture will be thick.
5. Add chocolate mixture to batter and mix until combined. Scrape down the sides of the bowl as needed to make sure everything is well combined.
6. Combine flour, baking soda and salt in a separate bowl.
7. Alternate adding the flour mixture and milk to the batter. Begin by adding half of the dry mix, then mix well. Add the milk and mix well, scraping down the sides as needed. Add the remaining flour mixture and mix until smooth.
8. Fill cupcake liners about 3/4 way. Bake for 15-17 minutes, or until a toothpick inserted comes out with a few crumbs.
9. Allow cupcakes to cool about 2-3 minutes, then remove to a cooling rack to finish cooling.
10. To make the frosting, combine the butter and shortening in a large bowl and mix until smooth.
11. Add 2 cups of powdered sugar and mix until smooth.
12. Add the cocoa, vanilla extract and 4 tablespoons of Baileys and mix until smooth.
13. Add remaining powdered sugar and mix until smooth.
14. Add remaining Baileys as needed and mix until smooth, keeping an eye on the consistency of the frosting so it doesn’t get too thin. Set aside.
15. When the cupcakes are cooled, make the chocolate ganache. Put the chocolate chips in a heat-proof bowl.
16. Combine the Baileys and heavy whipping cream in a microwave safe bowl or measuring cup and heat in the microwave until it just begins to boil.
17. Pour the hot cream over the chocolate chips and whisk until smooth.
18. Cut out the centers of the cupcakes. You can use a cupcake corer or a knife.
19. Fill the centers of the cupcakes with chocolate ganache.
20. Pipe the frosting onto the cupcakes. I used Ateco tip 808, a large round tip.
21. Use the remaining chocolate ganache to pipe onto the cupcakes for decoration, then add sprinkles if using.
22. Refrigerate cupcakes until ready to serve. Serve at room temperature. Cupcakes are best for 2-3 days.