Line a baking sheet with wax paper. Combine the oats, peanut butter, bitter and semisweet chocolate chips, toffee bits, butter and salt in a medium saucepan. Cook over medium heat, stirring frequently, until the chocolate chips melt, 3 to 5 minutes.
Scoop heaping tablespoons of batter onto the baking sheet and sprinkle each cookie with extra toffee bits. Freeze for 15 minutes before serving. The cookies can be stored in the refrigerator in an air-tight container for 1 week.