First Step: Prepare Oven and Pan. Preheat your oven to 350°F (175°C). Line a 9×13 inch (23×33 cm) baking dish with parchment paper or foil, lightly greasing if preferred to prevent the cookie bars from sticking.

Second Step: Make the Caramel Filling. In a small saucepan or microwave-safe bowl, melt together the unwrapped caramels, unsalted butter, and sweetened condensed milk. Heat over medium-low flame or in short 20-30 second microwave bursts, stirring frequently until smooth and fully melted. Remove from heat and allow the caramel mixture to cool slightly while you prepare the dough.

Third Step: Mix Dry Ingredients. In a medium bowl, whisk together the all-purpose flour, old fashioned oats, baking powder, and salt. This blends the foundational dry elements for the cookie dough, ensuring even texture and rise.

Fourth Step: Cream Wet Ingredients. Using a large mixing bowl or stand mixer, cream the softened or melted butter with peanut butter and light brown sugar until the mixture is fluffy and well combined. This process incorporates air, creating a tender cookie bar texture.

Fifth Step: Add Eggs and Vanilla. Add eggs one at a time to the creamed mixture, mixing thoroughly after each addition to bind the ingredients. Then incorporate vanilla extract for flavor depth.

Sixth Step: Combine Dry and Wet. Gradually add the dry ingredients to the wet mixture, stirring until just combined. Avoid overmixing to keep the bars tender.

Seventh Step: Add Chips and Toffee. Fold in the semi-sweet chocolate chips, peanut butter chips, and toffee bits evenly throughout the dough. This evenly distributes each distinct flavor and texture.

Eighth Step: Assemble Cookie Bars. Press two-thirds of the dough firmly and evenly into the prepared baking pan using clean hands or a greased spoon, creating the base layer. Pour the slightly cooled caramel filling evenly over this base. Then, drop the remaining dough by teaspoon-sized dollops over the caramel layer, spreading slightly for a rustic top.

Final Step: Bake and Cool. Bake the assembled bars for about 30 minutes, or until the top is golden and set but still slightly soft in the center. Allow the bars to cool completely in the pan to firm up before cutting into squares for the cleanest slices. Enjoy warm or chilled for different textures.