Preheat oven to 350 degrees. Coat a 9-by-13- inch baking pan with cooking spray. Line with a 9-by-21-inch sheet of parchment paper, leaving a 2-inch overhang on each short side. Put caramels and cream in a small saucepan; cook over medium heat, stirring occasionally, until caramels are melted, about 5 minutes. Let cool.
Stir together oats, flour, brown sugar, baking soda, and the salt in a large bowl. Blend in butter with a fork or your fingertips until mixture resembles coarse meal; press half of mixture onto bottom of lined pan. Bake until just set and starting to color around edges, about 20 minutes. Let cool in pan on a wire rack 5 minutes.
Sprinkle crust with chocolate chips; drizzle with caramel mixture. Top with remaining crumb mixture. Bake until pale golden, 20 to 25 minutes. Let cool completely in pan before cutting into squares.