Preheat oven to 350F and line a 9x9" square pan with parchment paper.
In a large mixing bowl, stir together the crushed crackers, toffee bits (reserving 2 tablespoons), and sweetened condensed milk until combined.
1 box (200g) Ritz crackers, 1 bag (200g) Skor toffee bits, 1 can (300ml) sweetened condensed milk
Transfer the mixture to the prepared pan. Press the mixture evenly and firmly into the pan.
Bake for 15 minutes. Remove from oven and immediately sprinkle with the white chocolate chips on top. Let stand for a minute to melt and then spread out the chocolate.
1 cup (170g) white chocolate chips
Sprinkle with the remaining toffee bits. Let cool in the fridge for 1-2 hours for the chocolate to set.
Notes
Leftovers can be stored in an airtight container at room temperature for 3-4 days, or in the fridge for up to a week.