Instructions
Step 1: Prepare
Preheat your oven to 350°F (175°C). Lightly grease a 9-by-13-inch baking pan. Do not line with parchment — the original recipe calls for an ungreased pan, but a light coating of cooking spray helps the base release cleanly after baking and cutting.
Step 2: Melt the Caramels
Unwrap all the caramels and place them in a small saucepan with the water or cream over low heat. Stir constantly and patiently — caramels melt unevenly and the mixture will look lumpy before it becomes smooth. This process takes 8 to 12 minutes over low heat; resist the temptation to increase the heat, as caramel scorches quickly. Once the mixture is completely smooth and pourable, remove it from the heat and set aside. It will remain pourable for 15 to 20 minutes while you prepare the oat base.
Step 3: Make the Oat Mixture
In a large mixing bowl, combine the flour, quick-cooking oats, brown sugar, melted butter or margarine, baking soda, and salt. Mix with a fork or your hands until a uniform, crumbly mixture forms — it should hold together when pressed but crumble apart when released. Reserve exactly 1 cup of this mixture and set it aside for the topping. Press the remaining mixture firmly and evenly into the bottom of the prepared pan. Use the bottom of a measuring cup or a flat spatula to press it down into a compact, uniform layer.
Step 4: Bake the Base
Bake the pressed oat base in the preheated oven for 10 minutes — just long enough to set it slightly and give it some structure to support the toppings. It will look pale and barely set at this point, which is correct. Remove from the oven and proceed immediately to the next step while the base is still hot.
