Slightly undercook these mouthwatering morsels for a molten effect.

　　

Ingredients

1/2 cup all-purpose flour

　　1/2 cup sugar

　　1/4 cup unsweetened Dutch-process cocoa powder

　　1/2 tsp baking powder

　　1/4 tsp salt

　　1 tsp espresso powder (optional)

　　2 tbsp unsalted butter, cut into pieces, room temperature

　　1/3 cup (about 3 oz) chopped dark chocolate

　　1 large egg

　　1 tbsp vanilla extract

　　1 cup powdered sugar

　　

Step 1

Preheat oven to 375° with racks in center and upper third. Line 2 baking sheets with parchment.

　　

Step 2

Whisk together flour, sugar, cocoa powder, baking powder, salt, and espresso powder (if using). Rub butter into dry ingredients until mixture resembles breadcrumbs. Stir in chocolate.

　　

Step 3

Whisk together egg and vanilla. Add egg mixture to chocolate mixture; stir with a fork until mixture is slightly moistened. Form dough into a ball; wrap in plastic; refrigerate 30 minutes.

　　

Step 4

Shape dough into tablespoon-size balls. Roll each in powdered sugar to coat; place on sheets 2" apart. Bake until just set but still slightly undercooked, about 10 minutes. Let cool on sheets 5 minutes; transfer to wire racks to cool completely. Serve warm.

　　Reprinted from Joy the Baker Homemade Decadence, by Joy Wilson, copyright 2014. Published by Clarkson Potter.