Irish coffee cupcakes with vegan Swiss meringue butter cream with green cupcake liners on a marble surface

Estimated Time & Nutrition Info for Boozy Irish Coffee Cupcakes

Prep Time: 20 minutes
Cook Time: 19-21 minutes
Total Time: 40-45 minutes
Makes: 12 cupcakes
Calories per Serving: ~320 (including buttercream)

This estimate includes frosting but may vary depending on ingredients used (e.g., different plant milks, oil types, or alcohol amounts).

HELPFUL NOTES + TROUBLESHOOTING

Why do I need to add vinegar to plant-based milk for baking?

Adding vinegar to plant-based milk creates a dairy-free “buttermilk-like” substitute. This improves the cupcake’s texture, helps with rise, and balances sweetness with a slight tang. If you skip this step, your cupcakes may be denser and less fluffy.

What’s the best plant-based milk for baking?

Unsweetened soy milk is the best choice because its high protein content mimics dairy milk, improving structure and texture. However, oat, almond, or cashew milk will also work.

Why use coffee in chocolate cupcakes?

Brewed coffee enhances the depth of chocolate flavor without making the cupcakes taste like coffee. If you don’t have coffee on hand, use hot water, but the flavor won’t be as rich.

Can I make these cupcakes without espresso powder?

Yes, but espresso powder works alongside the coffee to not only intensify the chocolate flavor, but to give an actual coffee flavor to the cupcakes. If skipping it, make sure to use strong brewed coffee instead of water to maintain depth.

Why did my cupcakes sink in the middle?

Cupcakes can sink for several reasons:

Underbaking: Ensure they are fully cooked before removing them from the oven. A toothpick should come out with a few moist crumbs, not wet batter.
Overmixing: Mixing too much incorporates excess air, which can collapse during baking. Stir just until combined.
Oven temperature issues: Ovens can run hot or cold. Use an oven thermometer to check accuracy and avoid opening the oven door too early.

How do I fix runny vegan buttercream?

If your buttercream is too soft or runny:

Chill it for 10-15 minutes, then re-whip.
Make sure the butter wasn’t too warm when mixing. Soft but not melted butter is ideal.
If the mixture looks curdled, keep mixing! It often comes together with continued whipping.

Can I make vegan buttercream ahead of time?

Yes! Store in the fridge for up to 3 days. Before using, let it come to room temperature and re-whip until smooth.

How should I store chocolate cupcakes?

Unfrosted cupcakes: Store in an airtight container at room temperature for up to 2 days or in the fridge for 4 days.
Frosted cupcakes: Store in the fridge for up to 2 days. Let them sit at room temperature for 15-20 minutes before eating for the best texture.

RECIPE

INGREDIENTS:

Cupcakes

1½ cups (180g) all-purpose flour
4 tablespoons (30g) unsweetened cocoa (Dutch-processed preferred)
½ teaspoon baking soda
1 teaspoon baking powder
1 teaspoon kosher salt (½ teaspoon if using table salt)
½ cup (100g) granulated sugar
½ cup (100g) dark brown sugar
⅓ cup (80ml) plant milk (room temperature)
1 tablespoon vinegar (white or apple cider)
⅓ cup (79ml) hot brewed coffee
⅓ cup (80ml) neutral oil (avocado or grapeseed)
2 teaspoons (3.3g) instant coffee or espresso powder
1 tablespoon vanilla extract

Swiss Meringue Buttercream

1½ cups (300g) sugar
170g aquafaba (liquid from 1 can of chickpeas)
¼ teaspoon cream of tartar
1¾ cups + 1 tablespoon (400g) vegan butter, cubed and room temperature
2-4 tablespoons Baileys Almande or whiskey
½ teaspoon vanilla extract
Pinch of kosher salt (skip if using salted butter)

Coffee Cocoa Dust (Optional Topping)

1 teaspoon Dutch-process cocoa (sifted)
½ teaspoon espresso powder
½ teaspoon powdered sugar (sifted)

Before You Start

Bring plant milk to room temperature and mix with vinegar (let sit for 5 minutes to curdle)
Drain a can of chickpeas and save the liquid for the buttercream
Line cupcake tins
Let butter come to room temperature
Brew coffee

Make the Cupcakes

Preheat oven to 350°F (177°C).
In a large bowl, whisk together:
- Granulated and brown sugar
- Vanilla extract
- Oil
No need to beat, just mix until combined.
Sift in cocoa powder, espresso powder, and salt. Pour in hot coffee and whisk until smooth.
Using hot coffee blooms the cocoa, enhancing its flavor.
Pour in curdled milk. Gently mix to combine.
Sift in flour, baking soda, and baking powder. Mix until just combined and scrape down the bowl to ensure everything is fully incorporated.
Be careful not to over-mix, as this can make the cupcakes dense. Mix just until no dry spots remain.
Fill cupcake tins evenly (about 45-48g of batter per cupcake).
Bake 19-21 minutes on the middle rack. Check doneness by:
- Lightly pressing the tops (they should spring back)
- Inserting a toothpick (it should come out mostly clean with a few crumbs)
Baking times may vary depending on oven type and calibration, so rely on visual and touch cues rather than just the timer.
Let cupcakes cool for 5 minutes in the pan, then transfer to a wire rack to cool completely before frosting.

Make the Swiss Meringue Buttercream

In a small saucepan, whisk together sugar, aquafaba, and cream of tartar.
Set your cooktop to medium/ medium-high heat and whisk constantly until the sugar is dissolved and the mixture is slightly warm, about 3 minutes.
Transfer to a stand mixer (or use a hand mixer) and beat on high speed with a wire whisk attachment for 8-10 minutes, until stiff, glossy peaks form.
Reduce to medium speed and gradually add room-temperature cubed butter, mixing until fully incorporated and fluffy.
Mix in Baileys (or whiskey), vanilla, and a pinch of salt. Beat for another minute until smooth.