These Best Ever Chocolate Cupcakes from Scratch are the perfect easy chocolate cupcakes - a one-bowl chocolate cupcake batter and fluffy chocolate frosting!
Preheat your oven to 350 degrees Fahrenheit and line cupcake tins with 28 to 30 paper liners.
Add the sugar, flour, cocoa powder, baking powder, baking soda, and salt to a large mixing bowl and whisk together to combine.
Measure the milk and the vegetable oil into a glass liquid measuring cup. Add the eggs and vanilla and whisk everything together with a fork.
Add the milk and egg mixture into the dry ingredients and mix together just until no streaks of flour remain.
Add the 1 cup of boiling water into the batter slowly, whisking everything together as you add the boiling water.
Once the batter comes together and the boiling water is combined throughout, portion the batter into the 28-30 prepared cupcake liners until each are about 2/3 full.
Bake at 350 degrees Fahrenheit for about 16-18 minutes or until a toothpick inserted into one of the cupcakes comes out clean.
While the cupcakes cool, mix the butter on high speed in a stand mixer or in a mixing bowl with a hand mixer until the butter is fluffy and creamy (about 3-4 minutes).
Add the powdered sugar one cup at a time and mix on medium high speed after each addition, scraping down the sides of the bowl.
Add the cocoa powder in with the last addition of powdered sugar and mix until combined.
Add the cooled melted chocolate and mix well until combined.
Add the milk one tablespoon at a time, mixing well after each addition, until the frosting reaches piping consistency.
Add the frosting to a piping bag fitted with an open star tip.
Pipe the frosting onto each of the completely cooled cupcakes in a circular motion and top each cupcake with sprinkles.
If making these cupcakes ahead of time, store in the refrigerator in an airtight container for up to 2 days ahead of time.