Preheat your oven to 350°F (175°C).

In a bowl, mix the flour, salt, and brown sugar. Cut in the butter using a pastry blender or fork until the mixture is crumbly.

Add the slightly beaten eggs and stir until incorporated. Mix in 1 1/2 cups of the chocolate chips and butterscotch chips.

Set aside 1 1/2 cups of the dough. Press the remaining dough into a 9x13-inch baking pan lined with parchment paper or lightly greased with cooking spray. Bake for 10 minutes.

Remove from the oven and evenly pour the sweetened condensed milk over the warm baked crust. Gently spread it into an even layer.

Reserve 1/3 cup of the toffee bits and sprinkle the remaining toffee bits on top.

Dollop the reserved dough over the toffee bits. Sprinkle with the remaining chocolate chips, butterscotch chips and toffee bits.

Bake for an additional 25-30 minutes, or until golden brown. Allow it to cool completely before serving.

For best flavor, let the bars sit overnight. Store covered in the refrigerator.

Notes:

For an extra crunch, you can add chopped nuts like pecans or walnuts to the dough before baking.