2. Bake crust according to package directions. Cool on a wire rack.
3. Slice 2 bananas. Spread half of warm dulce de leche in crust; top with sliced bananas. Spread remaining dulce de leche over bananas. Chill until cold, at least 2 hours.
4. Just before serving, combine heavy cream and sour cream in a bowl. Whip, using a mixer on high speed, until soft peaks form. Spread over pie. Slice remaining banana and use to garnish pie. Cut pie into wedges and serve.