Preheat oven to 350°; line 2 rimmed baking pans with parchment paper. In medium bowl, stir egg, sugar and peanut butter; fold in chocolate chips.
Roll dough into 11⁄2-inch balls; place 2 inches apart on prepared pans. Gently press each ball to fl atten slightly to about 1-inch thick; bake 12 minutes or until edges are set and bottoms are lightly browned. Cool cookies on pans 10 minutes; transfer to wire rack to cool completely. Makes about 16 cookies.
Sandwich 2 tablespoons ice cream between 2 cookies; repeat to make 7 more sandwiches. Serve immediately or freeze on parchment-lined cookie sheet 2 hours; transfer to a freezer-safe airtight container and freeze up to 1 month.