Step 1: Prepare Your Baking Pan

Preheat your oven to 350°F (177°C). Line a 9×9-inch baking pan with aluminum foil, leaving some overhang for easy removal. Lightly spray the foil with non-stick cooking spray.

Step 2: Melt Butterscotch and Butter

In a medium saucepan over medium to medium-low heat, add the butterscotch chips and butter. Stir continuously with a whisk. The butterscotch chips will take about 5 minutes to melt, and the mixture may look a bit strange at first, almost separating. This is normal. Keep whisking steadily until mostly smooth. Patience is key here; rushing the process with higher heat can cause the chips to seize.

Step 3: Create the Crust Mixture

Once the butterscotch and butter mixture is nearly smooth, remove from heat. Stir in the graham cracker crumbs until well combined. The mixture should resemble thick, wet sand.

Scoop out about 1 heaping cup of this mixture into a separate bowl and set aside for the topping.

Step 4: Form the Crust

Transfer the remaining butterscotch-graham mixture into your prepared pan. Press it down firmly with a spatula or the bottom of a measuring cup to form an even, compact crust. Set aside.

Step 5: Prepare the Cheesecake Layer

In a large bowl using a handheld mixer or a stand mixer fitted with the paddle attachment, beat the softened cream cheese on high speed until smooth and fluffy, about 2 to 3 minutes. Scrape down the sides of the bowl as needed.

Add the egg, sweetened condensed milk, vanilla extract, and salt. Beat on medium speed until fully combined. It’s normal if a few small cream cheese bits remain; keep mixing until the batter looks mostly smooth.

Step 6: Assemble the Bars

Pour the cheesecake mixture over the prepared crust, spreading it evenly with a spatula.

Sprinkle the reserved butterscotch-graham mixture evenly over the cheesecake layer to create a crumbly, delicious topping.

Step 7: Bake

Bake the bars for 32 to 35 minutes, or until the top is set but still slightly jiggly in the center. Lightly press your finger against the surface; it should feel springy.

If your oven runs hot or cold, start checking at the 25-minute mark to prevent overbaking.

Step 8: Cool and Chill

Allow the bars to cool at room temperature for about an hour. Then cover the pan and refrigerate for at least 2 hours, preferably longer, to allow the cheesecake layer to fully set before slicing and serving.