Ingredients
1 cup shortening1 cup packed light brown sugar1/2 cup sugar2 large eggs, room temperature1 teaspoon vanilla extract2-1/4 cups all-purpose flour1 teaspoon baking soda1 teaspoon salt1 package miniature semisweet chocolate chips (10 ounces) FILLING:1 vanilla bean3 large egg whites1/2 cup sugar1/2 teaspoon vanilla extract3/4 cup unsalted butter, room temperature
Preparation
Preheat oven to 350°. Cream shortening and sugars until light and fluffy. Beat in eggs and vanilla. In another bowl, whisk flour, baking soda and salt; gradually beat into creamed mixture. Stir in chocolate chips. Chill dough for 1 hour.
Shape teaspoonfuls of dough into 1-inch balls. Place 1-1/2 in. apart on ungreased baking sheets. Bake until edges begin to brown, 8-10 minutes. Cool on pans 2 minutes. Remove to wire racks to cool completely.
Meanwhile, for filling, split vanilla bean lengthwise. Using a sharp knife, scrape seeds from center into top of a double boiler over simmering water; discard bean. Add egg whites, sugar and vanilla extract. Whisking constantly, heat mixture until sugar is dissolved and a thermometer reads 160°, 8-10 minutes. Transfer to a stand mixer fitted with a whisk attachment.
Whisk egg white mixture on high until it cools to room temperature, 8-10 minutes. Reduce speed to medium; gradually add butter, 1 tablespoon at a time, beating well after each addition. Increase speed to high; beat until smooth.
To assemble, transfer filling to a reusable pastry bag. Pipe about 1 teaspoon on bottoms of half of the cookies; cover with remaining cookies. Store in airtight containers.
