Preheat oven to 350°F and line baking sheets with parchment paper. In a medium mixing bowl, sift together flour, baking soda and salt and set aside.In a stand mixer with the paddle attachment, cream the butter, peanut butter, sugar and brown sugar until lightand fluffy - about 8 minutes. Add egg and vanilla extract and beat until thoroughly combined. Reduce mixer to low, slowlyvadd the flourbmixture and beatvuntil just combined.

Using a small ice cream scoop (1 3/4 inch), scoop dough into 1-1/2 inch balls and roll in remaining 1/4 cup sugar to coat evenly and place on baking sheet about 2-inches apart. Gentlybpress the cookies with the back of a fork to create a crisscross pattern ( if tines stick, dip fork in cup of warm water in between each cookie). Transfer baking sheets to oven and bake 12-15 minutes, or until just golden. Transfer to cooking racks and let cool completely before making sandwiches

Slice bananas into 1/8-inch thick slices and fan slices on bottom sides of 12 cookies. Place 1 small scoop of chocolatechip ice cream on top of the banana slices and top with remaining cookie. Serve immediately or wrap cookies individually in plastic and freeze