Preheat oven to 350°F (175°C). Line a cupcake pan with paper liners.

In a bowl, whisk together flour, cocoa powder, baking soda, baking powder, and salt.

In another bowl, beat eggs, sugar, oil, buttermilk, and vanilla until smooth.

Stir dry ingredients into wet just until combined. Gently mix in hot water or coffee.

Fill cupcake liners about ⅔ full.

Bake 18–22 minutes, or until a toothpick inserted comes out clean.

Let cupcakes cool completely before filling and frosting.

Nutella Filling:

• Use a piping bag with a round tip or a small spoon to fill each cooled cupcake with 1–2 teaspoons of Nutella.

• Optional: Scoop out a small hole from the center before filling.

Nutella Buttercream Frosting Ingredients:

• ½ cup (115g) unsalted butter, softened

• ½ cup (120g) Nutella

• 1½–2 cups (180–240g) powdered sugar, sifted

• 1–2 tbsp milk or heavy cream

• ½ tsp vanilla extract

Nutella Buttercream Frosting Instructions:

1. Beat softened butter and Nutella together until creamy and smooth.

2. Gradually add powdered sugar, mixing well after each addition.

3. Add milk or cream one tablespoon at a time until desired consistency is reached.

4. Stir in vanilla extract. Beat frosting until light and fluffy.

5. Frost the cooled cupcakes with the Nutella buttercream.