Preheat the oven to 350°F. Line baking sheets with parchment paper. Beat the butter at medium speed with an electric mixer until creamy; gradually add the sugars, beating well. Add the egg and vanilla; beat well.

Stir together the flour, baking soda, and salt; gradually add to the butter mixture, beating at low speed after each addition. Stir in the pretzels, toffee candy, and chocolate. Drop the dough by heaping tablespoonfuls 1 inch apart onto prepared baking sheets.

Bake at 350°F for 12 to 14 minutes or until golden brown. Cool on baking sheets 5 minutes. Transfer to wire racks, and cool completely (about 20 minutes).