Preheat oven to 350°
Prepare a 13x9 pan with baking spray or shortening and flour.
In a bowl with a mixer cream the butter until smooth, add oil and sugar.
Add in the eggs and mix until combined.
In a separate medium bowl mix whisk four, cocoa, baking soda and salt.
In a liquid measuring cup add milk and vinegar and give it a stir, allow it to rest 1 minute.
Remove 2 tablespoons of milk mixture and add the coffee granules and mix to combine, heat in the microwave for 10 seconds if needed, so the granules dissolve. Pour back into the milk mixture.
Alternate the flour and milk mixture adding each to the butter and sugar mixture. Add 1/3 of the flour mixture, then 1/3 of the milk mixture and continue mixing until incorperated.
Scrape down the sides and bottom of the bowl, now add the Irish Cream and give it a final mix on medium low for 30 seconds to mix the batter together.
Pour the batter into the prepared pan.
Bake for 35-40 minutes or until a toothpick comes out clean.
Cool in the pan completely for 15 minutes if you're turning out onto a cooling rack or leave in the pan to completely cool at least 30 minutes before frosting.