Filled Cupcakes with Curd, Ganache or Cream

Before you start

A filled cupcake hides a spoonful of something soft in the center: tart curd, rich ganache or light whipped cream. The method works with any sturdy baked cupcake, such as vanilla, chocolate or lemon. What matters is the core, the filling's texture and keeping the two in balance so the cupcake still holds together when you bite into it.

Remove a core about 2.5 cm (1 in) wide and two-thirds of the way down. Too narrow and the filling hardly registers; too deep and it leaks through the base. Fillings must be thick enough to stay put: chilled curd, ganache cooled until it holds a peak, or cream stabilized with mascarpone. Each cupcake takes about 1 tablespoon (15 to 20 g). The frosting then seals the opening.

Ingredients

• Base12 standard cupcakes, baked and completely cooled
• about 400 g (2 cups) buttercream or other frosting
• Option 1: lemon curd100 g (½ cup) granulated sugar
• 2 large eggs
• 80 ml (⅓ cup) fresh lemon juice — about 2 lemons, plus 1 tsp zest
• 60 g (4 tbsp) unsalted butter — cubed
• Option 2: ganache115 g (4 oz) semisweet chocolate — finely chopped
• 120 ml (½ cup) heavy cream
• Option 3: stabilized cream180 ml (¾ cup) cold heavy cream
• 60 g (¼ cup) cold mascarpone
• 2 tbsp powdered sugar
• ½ tsp vanilla extract

Method

1. For lemon curd: whisk the sugar, eggs, lemon juice and zest in a small saucepan. Cook over medium-low heat, whisking constantly, for 6 to 8 minutes, until thick enough to coat a spoon and about 77°C (170°F). Off the heat, whisk in the butter, strain, press plastic onto the surface and chill for 1 hour.
2. For ganache: bring the cream to a simmer, pour it over the chocolate, wait 2 minutes and stir until smooth. Cool at room temperature for about 1 hour, stirring occasionally, until it is thick like peanut butter and holds a soft peak.
3. For stabilized cream: whip the cream, mascarpone, powdered sugar and vanilla on medium speed to firm peaks. Use it right away; it needs no chilling.
4. Core each cupcake: push an apple corer or a 2.5 cm (1 in) cutter straight down about two-thirds of the depth, twist and pull out the plug. With a paring knife, cut a cone at an angle instead. Keep the tops of the plugs if you want caps.
5. Spoon your chosen filling into a piping bag fitted with a round tip, or a zip-top bag with the corner snipped. Pipe about 1 tablespoon into each hole, until level with the top.
6. Trim the cupcake plugs to a 5 mm (¼ in) disk and press one on each to cap the filling, or skip this and go straight to frosting.
7. Pipe or spread the frosting over each cupcake, covering the opening fully so the filling is sealed.

Tips for success

• Snack on the leftover cores or crumble them over the frosting for decoration.
• Match textures with flavors: lemon curd in vanilla cupcakes, ganache in chocolate, and stabilized cream in either for a lighter bite.
• Curd and ganache recipes here make extra. Leftover curd is good on toast; leftover ganache rewarms into a sauce.

Substitutions

Homemade lemon curd

Good store-bought curd works. Stir it smooth and chill it first so it is firm enough not to soak into the crumb.

Mascarpone in the cream

Use 2 tbsp instant vanilla pudding mix whisked into the cream; it holds well but tastes sweeter.

Semisweet chocolate

Milk or white chocolate ganache needs less cream to set: about 80 ml for 115 g milk chocolate, and 60 ml for 115 g white chocolate.

Variations

Jam-filled cupcakes

Use about 1 tablespoon of seedless jam per cupcake, warmed slightly and cooled so it pipes, and top with vanilla buttercream.

Salted caramel cupcakes

Fill with thick, cooled salted caramel sauce and add a few flakes of salt on the frosting.

Troubleshooting

Filling soaked into the cake

It was too thin or warm. Chill curd until firm, cool ganache until it holds a peak, and fill the cupcakes only once they are completely cool.

Filling leaked out the bottom

The core went too deep. Stop about 1 cm above the base so the bottom stays intact.

Curd turned lumpy

The heat was too high and the eggs scrambled. Cook over medium-low, whisk constantly and strain the finished curd through a sieve.

Storage

Cupcakes filled with curd or cream are perishable. Keep them covered in the refrigerator for up to 2 days and set them out for 20 minutes before serving. Ganache-filled cupcakes keep at cool room temperature for 1 day.

Safety notes

Lemon curd contains egg and is cooked on the stovetop past 71°C (160°F); refrigerate curd- or cream-filled cupcakes and do not leave them out more than 2 hours. Contains wheat, egg and milk.