Line or spray 12 muffin tins. Preheat oven to 350℉.
In a medium mixing bowl, add the flour, sugar, baking powder, baking soda and salt. Whisk together until combined and set aside.
In a large mixing bowl, add the egg, milk and canola oil. Whisk for about 30 seconds until well combined. Add in the vanilla and vinegar and whisk an additional 20 seconds.
Add the cocoa powder and espresso to the wet mixture. Slowly and carefully pour in the boiling water while whisking to combine.
Add the dry mixture to the wet mixture and whisk together until just combined. Fill each muffin cup about 3/4 full, adding about 1/4 cup to each tin.
Bake for 18-22 minutes or until a toothpick inserted in the centre comes out clean. Allow to cool in the tins for 5 minutes before transferring to a wire rack to cool. Store in an airtight container for up to 3 days and frost with icing of choice.
How to Make the Frosting
If making my chocolate cinnamon cream cheese frosting, to the bowl of a stand mixer, add the cream cheese and butter. Beat on high speed for 3 minutes, scraping down the sides of the bowl.
Add in half the amount of icing sugar and mix at low speed until starting to incorporate. Then beat at high speed for additional minute. Add in the rest of the sugar and the cocoa powder. Again mix at low speed until incorporated and mix additional 30 seconds.
Add in the ground cinnamon, vanilla extract, salt and lemon juice. Beat on high speed for additional 3-4 minutes or until light and fluffy. If your frosting is a bit too thick to pipe, add in milk, 1 tbsp at a time until you reach the desired consistency.
To get the air bubbles out, mix the frosting by hand with a spatula for 1-2 minutes. This helps give you a smooth frosting when piping. Then pipe however you desire. I used a Wilton 1M tip for the pictures. As this is a cream cheese frosting, I would eat the cupcakes right away once you frost them or store in the fridge. Take them out about 30 minutes before serving and enjoy!
Keyword chocolate cupcakes, chocolate cupcakes from scratch, easy chocolate cupcakes