Line 2 standard baking sheets with wax paper. Set aside.
In a double boiler on the stovetop, melt together the chocolate chips and shortening over simmering water. Don't let the water touch the bottom of the bowl. Stir periodically until completely smooth. (Alternatively, melt in a large microwave safe bowl on 50% power or using the melt function. Melt in 30-45 second intervals stopping to stir each cycle. Repeat the process until completely smooth.)
Use a non-stick spatula to stir in the cashews and 1 cup toffee bits. Mix until all of the nuts are covered and evenly distributed.
Use a tablespoon or small scoop to drop clusters onto the prepared sheet pan at least 1-inch apart. Sprinkle the tops with the remaining toffee bits while the chocolate is still wet.
Allow to sit at room temperature until set or you can refrigerate to speed up the process.
Store in an airtight container chilled or at room temperature for up to 2 weeks. If chilled, bring to room temperature for serving.
Notes
Vegetable Shortening - For this recipe, I like to use a small amount of vegetable shortening to thin the chocolate just a bit and give the clusters their shine when they dry. If you have an aversion to using shortening you could substitute with coconut oil, which will also stay solid at room temperature and can be used in its place in the same amount.
Chocolate - You could use the same amount of dark chocolate chips, white chocolate, milk chocolate baking chips or a combination for this cashew clusters recipe.
Toffee Bits - The toffee bits used in this recipe aren't coated with chocolate. If you're unable to find them you could use the chocolate coated version of Heath bits. You could also garnish these cashew clusters with flaky sea salt.
Nuts - This recipe could be adapted using peanut, walnuts or almonds.
Use a Double Boiler or Large Bowl - You can melt the chocolate and shortening together in a microwave safe bowl or using a double boiler on the stovetop.
Make Your Own Double Boiler - If you don't have a double boiler, you can create one using a heat safe bowl fitted over a pot of simmering water. It's important not to let the simmering water touch the bottom of the bowl.
Gifting - These cashew clusters would make a thoughtful and delicious holiday treat for gifts. You could put them into a jar or cellophane bag and tie the top with a pretty ribbon for a great gift for friends, family and neighbors. You can also arrange them in a festive candy tin with a note attached or pop them into the kids Easter baskets and Valentine's Day treats.