Preheat oven to 375 degrees. Lightly grease donut pans (this one is my favorite!). Set aside.
Combine flour, sugar, cocoa powder, espresso powder, and baking soda. Stir gently to combine.
In a small bowl, beat together the vanilla, egg, sour cream, coffee, coffee creamer and oil. Stir wet ingredients into the dry ingredients and mix until just combined.
Transfer batter to a large ziploc bag. Cut off the corner and, using like a pastry bag, pipe donut batter into the donut pan. Bake in preheated over for 8-10 minutes. Let cool completely.
Combine powdered sugar, 3 Tbsp milk and peppermint extract in a bowl. Whisk until smooth. Add additional milk as necessary to reach desired consistency. Dip donuts into glaze and sprinkle with crushed candy cane pieces.