Preheat oven to 350°. Coat a 9″x 13″ baking pan with cooking spray. Line with parchment paper, leaving about a 2-inch overhang on the short ends.
In a large bowl, stir together oats, flour, brown sugar, baking soda, and salt. Mix in butter, using a fork or your fingers, until the mixture resembles coarse meal. Press half of mixture onto the bottom of prepared pan.
Bake until just set and starting to brown around the edges (about 20 minutes). Cool in pan on wire rack for 5 minutes.
While crust is baking, cook caramels and cream in a small saucepan over medium heat. Stir occasionally, until caramels are melted. Remove from heat and let cool slightly.
Sprinkle partially baked crust with chocolate chips. Drizzle caramel mixture over chips and crust. Top with remaining crumb mixture.
Bake 20-25 minutes, or until pale golden. Cool completely in pan before cutting into bars.