1-First Step: Prep the pan and oven Start by preheating your oven to 350°F. Line a 9×13 inch baking dish with parchment paper, leaving a little overhang on the sides so you can lift the bars out later with ease. This small step makes cleanup simpler and keeps the gooey caramel from sticking to the pan.

2-Second Step: Make the caramel filling Unwrap 11 ounces of caramels and place them in a small saucepan or a microwave-safe bowl with 14 ounces of sweetened condensed milk and 4 tablespoons of unsalted butter. If using the microwave, heat on medium in 30-second bursts, stirring after each round. If you prefer the stovetop, warm it over medium-low heat and stir often until everything turns smooth and glossy. Set the mixture aside once melted.

3-Third Step: Mix the dry ingredients In a small bowl, combine 2 cups all-purpose flour, 1 cup old fashioned oats, 2 1/2 teaspoons baking powder, and 1 teaspoon salt. Stir well so the leavening and salt are evenly mixed through the flour. This helps the Peanut Butter Chocolate Chip Cookie Bars bake evenly and keeps the texture balanced.

4-Fourth Step: Cream the butter, peanut butter, and sugar In a large bowl or stand mixer, beat 12 tablespoons unsalted butter, 1/2 cup creamy peanut butter, and 2 cups light brown sugar together until fluffy. This step adds air to the dough and gives the bars their soft, rich texture. Use regular creamy peanut butter rather than natural peanut butter for the best structure and flavor in these Peanut Butter Cookie Bars.

5-Fifth Step: Add the eggs and vanilla Add the 2 large eggs one at a time, mixing well after each addition. Then mix in 1 tablespoon vanilla extract. Using room-temperature eggs helps the dough blend smoothly, which means a more even bake and a softer bite.

6-Sixth Step: Bring in the dry mix Gradually add the flour mixture to the butter mixture, stirring only until combined. Try not to overmix, since that can make the bars dense. The dough should be thick and sturdy, which is exactly what you want for layered cookie bars.

7-Seventh Step: Fold in the mix-ins Stir in 2 cups semi-sweet chocolate chips, 1 cup peanut butter chips, and 1 cup toffee bits. These add-ins give the bars their signature flavor and make each square feel special. If you want to play with the flavor, this is the stage where you can adjust the chocolate blend or add a few chopped nuts.

8-Eighth Step: Build the first layer Spread about two-thirds of the dough evenly in the bottom of the prepared pan. Use your hands or the back of a spoon to press it down into an even layer. It does not need to be perfect, but try to cover the base so the caramel stays tucked inside.

9-Ninth Step: Add the caramel center Pour the caramel mixture evenly over the dough layer. Spread it carefully so it reaches most of the corners without mixing into the cookie dough too much. For a sweet-and-salty twist, you can sprinkle a little sea salt over the caramel before adding the top layer.

10-Tenth Step: Add the top dough pieces Drop the remaining dough on top by the teaspoon. Small pieces are just fine, and you do not need to cover every inch. The gaps will bake together into a craggy, golden top that looks rustic and inviting.

11-Final Step: Bake, cool, and cut Bake for about 30 minutes, or until the top is golden brown and the center is set but still a little soft. Watch closely near the end so the bars do not overbake. Let them cool completely before slicing, because the caramel needs time to firm up. Once cool, lift them out with the parchment overhang and cut into 24 bars.