Line a cookie sheet with a silicone mat or wax paper.
Melt 1 1/2 cups milk chocolate chips via microwave or double boiler.
Using a spatula, spread it over the mat or paper as evenly as you can get it.
Freeze for 30 minutes.
Mix together cookie butter, powdered sugar, and butter.
Using your hands, press the cookie butter over the frozen chocolate - again as evenly as you can get it.
Melt the last 1 1/2 cups milk chocolate chips via microwave or double boiler. Then spread with your spatula over the cookie butter layer, as evenly as possible.
Top with sea salt and place back in freezer for at least one hour, but overnight is better.
Break into pieces! Store in the refrigerator in an airtight container.