Homemade Chocolate Sandwich Cookies

Before you start

These are a from-scratch take on the famous chocolate sandwich cookie: two thin, crisp, nearly black chocolate wafers holding a dense, sweet vanilla cream. The wafers rely on Dutch-process cocoa for their dark color and mellow flavor; black cocoa, if you can find it, makes them darker still and closer to the store-bought taste.

The wafers need to be thin and baked through so they snap rather than bend. Roll the dough between parchment and chill it before cutting, which keeps the rounds crisp-edged. Because the dough is so dark, you cannot judge doneness by color; go by time and by a top that feels dry and firm. The filling uses part shortening so it holds its shape at room temperature, with butter for flavor.

Ingredients

• Wafers150 g (1¼ cups, spooned and leveled) all-purpose flour
• 50 g (½ cup plus 1 tbsp) Dutch-process or black cocoa powder
• ¼ tsp baking soda
• ¼ tsp fine salt
• 115 g (½ cup) unsalted butter — softened
• 130 g (⅔ cup) granulated sugar
• 1 large (about 50 g) egg — room temperature
• 1 tsp vanilla extract
• Filling60 g (4 tbsp) unsalted butter — softened
• 55 g (¼ cup) vegetable shortening
• 240 g (2 cups) powdered sugar — sifted
• 2 tsp vanilla extract
• Pinch fine salt
• 1 to 2 tsp milk — only if needed

Method

1. Whisk the flour, cocoa, baking soda and salt together.
2. Beat 115 g butter and the granulated sugar on medium speed for 2 minutes. Add the egg and vanilla and beat until smooth.
3. Add the dry ingredients on low and mix until a uniform dark dough forms. Divide it in half and roll each half between parchment to 3 mm (⅛ in) thick. Stack the sheets on a tray and chill for 30 minutes, until firm.
4. Heat the oven to 165°C (325°F) and line the baking sheets with parchment. Cut 5 cm rounds and space them 2 cm (¾ in) apart. Re-roll and chill scraps. If you like, prick each round twice with a fork or press a pattern with a stamp.
5. Bake one sheet at a time for 12 to 14 minutes, until the tops look matte and feel firm when touched lightly. Cool on the sheet for 5 minutes, then on a rack. The wafers crisp as they cool.
6. For the filling, beat the butter and shortening until smooth. Add the powdered sugar, vanilla and salt and beat on low, then medium, until thick and creamy. It should be stiff enough to hold a ball; add milk by the teaspoon only if it is too stiff to pipe.
7. Pair the wafers by size. Pipe or spoon about 2 teaspoons (11 g) of filling onto the flat side of one wafer, top with another and twist gently to spread the cream to the edge.

Tips for success

• Black cocoa is very low in fat and acidity; using all black cocoa makes a dry, dusty wafer, so blend it half and half with regular Dutch-process cocoa.
• Use a scale for the filling portions. Even amounts give tidy, matching sandwiches.
• Let filled cookies sit for an hour before serving so the cream sets.

Substitutions

Vegetable shortening

Use all butter for a richer filling. It will be softer and less white, and it can squeeze out in a warm room.

Dutch-process cocoa

Natural cocoa makes a lighter brown, more acidic wafer. Swap the baking soda for ½ teaspoon baking powder to keep the balance.

Vanilla filling

Beat 2 tablespoons of seedless raspberry jam or ½ teaspoon peppermint extract into the filling for a flavored center.

Variations

Double-stuffed

Use 4 teaspoons of filling per cookie and make one and a half times the filling recipe.

Mint chocolate

Flavor the filling with ½ teaspoon peppermint extract and tint it pale green with gel coloring.

Troubleshooting

Wafers are soft and cakey

They were rolled too thick or underbaked. Keep the dough 3 mm thick and bake until the tops feel firm; they should snap once cool.

Wafers taste burnt

The oven ran hot and dark dough hid the browning. Use 165°C, check with an oven thermometer and bake by time and touch.

Filling is grainy

The powdered sugar was lumpy or the fats were cold. Sift the sugar and beat the butter and shortening until smooth before adding it.

Storage

Store filled cookies in an airtight container at room temperature for up to 1 week. Unfilled wafers keep for 2 weeks airtight or 3 months frozen. Keep the filling covered in the refrigerator for up to 1 week and bring it to room temperature before using.

Safety notes

Contains wheat, egg and milk. The raw dough contains egg and flour and is not safe to eat before baking.