Preheat oven to 350°F. Place oven rack in the middle of the oven.
Spray a 9X13 inch cake pan with non-stick baking spray and set aside.
Add the flour, sugar, cocoa, baking powder and salt to a large bowl and whisk until combined, or add to the bowl of a stand mixer and whisk on low.
In another medium bowl combine Baileys Irish Cream, vegetable oil, vanilla extract and eggs and whisk until fully combined.
Add the wet ingredients to the dry ingredients and beat on medium speed until well combined.
Slowly add the hot water to the batter and mix on low speed until well combined. Make sure to stop and scrape down the sides and bottom of the bowl with a spatula.
Pour batter into the prepared pan and bake for 30-32 minutes, or until a toothpick comes out with just a few moist crumbs. I baked mine for exactly 30 minutes.
Remove cake from oven. Using the end of a spatula or a large straw, even a pen will work if you don't have anything on hand, poke holes all over the cake.