Beat butter on high until soft, about 30 seconds.
Add sugar. Beat on medium-high until light and fluffy, about 3 minutes.
Add eggs one at a time, beat for 30 seconds between each.
Measure out coffee and milk together.
Add about a fourth of the flour to the butter/sugar mixture and beat to combine.
Add about one third the coffee/milk mixture and beat until combined.
Repeat above, alternating flour and coffee and ending with the flour mixture.
Bake for 22-25 minutes until a cake tester comes out clean.