Cut apples into 1/4" rounds. 

Using a biscuit cutter, cut each apple round into a perfectly-shaped circle.

Using a small round cookie cutter, cut the center out of each apple round. This will leave you with a donut shape. Set apple slices aside.

Mix together peanut butter, maple syrup, and salt. 

Using your hands, mound about a teaspoon of the sweetened up peanut butter mixture onto each apple slice. Set aside. 

Melt one bag of dark chocolate chips in a double boiler and then dip each peanut butter-coated apple round in the chocolate.

Before the chocolate hardens, add desired toppings. 

Lay each apple donut on a parchment paper-lined baking sheet and refrigerate to set.