Preheat the oven to 350°F (175°C). Lightly grease a 9" x 13" x 2" baking pan. If you prefer, you can first line the pan with parchment paper.
Combine the flour, oats, brown sugar, baking soda, and salt in a large mixing bowl. Add the butter, and mix on low speed until combined. (The mixture will be loose but should hold together when pinched.)
Press half of the flour mixture into the bottom of the prepared pan. Bake for 10 minutes.
Place the caramels and cream in a heavy saucepan. Cook over medium-low heat, stirring frequently, until the caramels melt and the mixture is smooth.
Pour the caramel mixture over the partially baked crust, and spread evenly. Let the caramel cool for about 5 to 10 minutes to allow it to thicken a bit.
Scatter the chocolate chips and nuts over the caramel. Sprinkle the remaining crust mixture over the top.
Bake 20 to 25 minutes, or until the top is golden brown.
Cool in the pan on a wire rack before cutting into bars.
Video
Notes
Store in an airtight container at room temperature up to 4 days.