Mini Chocolate Chip Sandwich Cookies

Directions

1. Preheat oven to 350°. Cream shortening and sugars until light and fluffy, 5-7 minutes. 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.
2. 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.
3. 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.
4. 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.
5. 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.