Heat oven to 375°F. Grease bottom and sides of 15x10x1-inch pan with shortening or cooking spray (do not use dark pan).
In large bowl, beat 3/4 cup butter and 1/3 cup brown sugar with electric mixer on medium speed until light and fluffy. Add egg; beat until well blended. On low speed, beat in flour until dough begins to form. Press dough in pan.
Bake 12 to 17 minutes or until edges are light golden brown. Meanwhile, in 2-quart saucepan, heat 1 cup butter, 3/4 cup brown sugar and the corn syrup to boiling over medium heat, stirring frequently. Boil 2 minutes without stirring.
Quickly stir pecans into corn syrup mixture; spread over partially baked crust. Bake 20 to 23 minutes or until filling is golden brown and bubbly.
Immediately sprinkle chocolate chips evenly over hot bars. Let stand 5 minutes to soften. With rubber spatula, gently swirl melted chips over bars. Cool completely, about 1 hour. For bars, cut into 24 squares (6 rows by 4 rows), then cut each square in half to make triangles. Store in refrigerator.