Velvety Nutella Buttercream Cupcakes

For the Cupcakes:

• 2 Eggs, the cornerstone of any cake's structure
• 1 cup of Granulated Sugar, fine and sweet
• 1 ½ cups of Flour, sifted to airy perfection
• 1 ½ teaspoons of Baking Powder, for a gentle rise
• 1 teaspoon of Baking Soda, for a tender crumb
• ⅓ cup of Cocoa Powder, rich and robust
• ½ teaspoon of Kosher Salt, a subtle touch to balance sweetness
• ⅓ cup of Nutella, for a hazelnut chocolate swirl
• ⅓ cup of Vegetable Oil, for a moist texture
• 1 cup of Hot Coffee, to deepen the chocolate flavor
• 2 teaspoons of Vanilla Extract, a fragrant embrace

For the Nutella Buttercream:

• 230 grams of Butter, softened to a pliable silkiness
• 1 ½ cups of Powdered Sugar, the sweetness sifted
• ⅓ cup of Cocoa Powder, for a double chocolate note
• 1 teaspoon of Vanilla Extract, an aromatic whisper
• ¼ teaspoon of Kosher Salt, to heighten the flavors
• ½ cup of Nutella, the star of this sweet show
• ⅓ cup of Heavy Cream, whipped to a luxurious texture

Baking the Delights:

1. Begin by preheating your oven, lining a cupcake pan with whimsical liners.
2. Whisk together the dry cupcake ingredients, a melody of dry textures.
3. Blend the Nutella, oil, vanilla, and eggs until they’re just shy of fully combined, then welcome the hot coffee with a final mix.
4. Fill the liners using an ice cream scoop for perfect portions, and bake until they pass the toothpick test.
5. Once baked, allow the cupcakes to cool, a pause that’s essential before adorning with frosting.

Creating the Nutella Buttercream:

1. Whip the softened butter until it's light and airy.
2. Gradually incorporate the powdered sugar and cocoa, a cloud of sweetness.
3. Swirl in the Nutella, and then the heavy cream, until the mixture is irresistibly smooth.

Assembling with Care:

1. When the cupcakes have cooled, hollow out a small heart in the center of each.
2. Fill the hearts with pure Nutella love, a secret surprise within.
3. Pipe a generous swirl of the Nutella buttercream on top, a starry finish.

Baker’s Notes for Perfection:

• The coffee is a silent partner; it won't stand out but will amplify the chocolate notes.
• Room temperature ingredients blend seamlessly for a smooth batter.
• Avoid overmixing to maintain the cupcakes' delicate crumb.
• Spoon and level your flour for precision and tenderness.
• Allow the cupcakes a full cool down so the buttercream sits proudly atop.
• Freshness in your leaveners is crucial; they're the hidden heroes of texture.

Serve these Nutella buttercream cupcakes as a testament to your baking finesse, each bite revealing a tender crumb, a heart of Nutella, and a swirl of buttery chocolate. Patience in preparation leads to the sweetest rewards!