In a large bowl, beat softened butter with mixer until smooth. Add sugar and vanilla and whip until light and fluffy, about 2 minutes. Beat in the eggs one at a time, beating well after each addition. Mix in the milk and sour cream until smooth

In another bowl add remaining dry ingredients, mixing well. Add 1/3 of the dry ingredients to the butter mixture, and mix until incorporated. Add another 1/3 of the dry in and mix, repeat until batter is smooth.

Pour batter into 2 parchment lined 9” pans, or if making shamrock design as above pour into 2 baking sheets lined with parchment paper.

Bake at 350°F for 30-40 minutes, or until fully cooked and edges start to turn golden. Allow to cool completely before removing from pan, or cutting into heart shapes.

For the frosting, combine all ingredients together and beat until smooth and creamy. Spread between the layers of the cake (but not the top).

For the ganache, in a saucepan, heat cream as hot as you can but remove before it begins to boil. Remove from heat and pour into a mixing bowl filled with the chocolate, butter, and whiskey. Cover and let stand 10 minutes. Whisk until smooth. Spread over the top of the cake(s).

For the Baileys sugar crystals, in a small dish add just enough Baileys until it has the consistency of wet sand. Spread out onto a silicone lined baking pan and let sit on counter until completely dry and hardened. Every few hours you can stir the mixture around if you want. Once completely dry, use a sharp edge/blade to break up any large pieces.