Chocolate Malt Sandwiches

Malted-milk powder, a combination of powdered milk, wheat flour, and malted barley, adds a rich component to both these cookies and their filling. A double dose of chocolate (chopped semisweet and lots of cocoa powder) makes these sandwich cookies extra decadent, makes about 1-1/2 dozen for the cookies:

2 cups plus 2 tablespoons all-purpose flour

1/2 cup unsweetened Dutch-process cocoa powder

1/4 cup plain malted milk powder

1 teaspoon baking soda

1/2 teaspoon coarse salt

1 cup (2 sticks) unsalted butter, room temperature

1-3/4 cups sugar

large egg

teaspoons pure vanilla extract

1/4 cup créme fraiche

tablespoons hot water

for the filling:
• 10 ounces semisweet chocolate, coarsely chopped
• 4 tablespoons (1/2 stick) unsalted butter, cut into small pieces
• 1 cup plain malted milk powder
• 3 ounces cream cheese, room temperature
• 1/4 cup plus 2 tablespoons half-and-half
• 1 teaspoon pure vanilla extract

• Preheat oven to 350F. Make cookies: Sift together flour, cocoa powder, malted milk powder, baking soda, and salt. With an electric mixer, beat butter and sugar on medium-high speed until pale and fluffy. Mix in egg, vanilla, créme fraiche, and hot water. Reduce speed to low; mix in flour mixture.
• Space tablespoon-size balls of dough 3-1/2 inches apart on parchment paper-lined baking sheets. Bake until flat and just firm, 10 to 12 minutes. Let cool on parchment on wire racks.
• Make filling: Melt chocolate and butter in a heatproof bowl set over a pan of simmering water, stirring. Let cool. With an electric mixer, beat malted milk powder and cream cheese on medium speed until smooth. Gradually mix in half-andhalf, chocolate mixture, and vanilla. Refrigerate, covered, until thick, about 30 minutes. Mix on high speed until fluffy, about 3 minutes.
• Assemble cookies: Spread a heaping tablespoon filling on the bottom of one cookie. Sandwich with another cookie. Repeat. Cookies can be refrigerated between layers of parchment in airtight containers at room temperature up to 3 days.