Heat oven to 350°F. Grease 3 (12-cup) mini fluted tube cake pans with shortening.
In bowl of electric mixer fitted with paddle, mix granulated sugar, flour, cocoa, baking soda, baking powder and salt on low speed.
In a medium bowl, beat egg, buttermilk, oil, and vanilla with whisk until well blended. Slowly beat buttermilk mixture into dry ingredients just until incorporated. Gradually beat in beer and hot coffee until thoroughly incorporated. Pour batter evenly into fluted muffin cups, filling each about half to two-thirds full. (See notes)
Bake 12 to 14 minutes or until toothpick inserted in center of each cake comes out clean. Cool in pan 10 minutes. Place cooling rack upside down over muffin cups; tap pan against work surface to make sure cakes have loosened. Remove pan; cool cakes at least 15 minutes.
In large bowl, beat cream cheese and milk with electric mixer on medium speed until smooth. Gradually add powdered sugar, beating until smooth. Pour glaze over cooled cakes, allowing some to flow over sides.
If you only have 1 pan, refrigerate batter during first baking; repeat twice with remaining batter to make 30 cakes.