This frosting keeps well at room temperature for a few hours, however if it starts to get too warm or you are not eating the cupcakes right away, place them in the refrigerator.
Preheat oven to 375 degrees. Line a 12-cup muffin tin with baking cups. In a large bowl, whisk together flour, cocoa, baking soda, salt, and sugar. In a separate bowl, whisk together coconut oil, espresso powder, almond milk, and vanilla. Whisk wet ingredients into dry ingredients, until combined. Quickly stir in the vinegar until incorporated.
Divide batter evenly between muffin cups (scant 1/3 cup per cupcake). Bake until tops spring back when lightly touched, about 18 minutes. Cool 5 minutes in pan, then transfer to wire rack to cool completely. Top cupcakes with vegan frosting (about 3 tablespoons per cupcake).