California Walnut Turtle Squares

In medium bowl, mix together flour and sugar; blend in butter until crumbly. Press into ungreased 13 x 9-inch pan, lined with heavy-duty foil. Spread walnuts in one layer over dough. Bake in 350°F (175°C) oven for about 20 to 25 minutes, or until walnuts are lightly toasted and base is lightly browned on edges. Remove from oven; set aside. In medium saucepan, combine unwrapped caramels and cream. Warm over medium to low heat, stirring constantly, until caramels melt. Immediately drizzle caramel mixture over nuts. Scatter chocolate chips over top; let stand 2 to 3 minutes. Swirl through chocolate with knife; allow to cool before cutting into bars.