Start by rinsing the apple thoroughly under cold water to remove any wax or residue. Using an apple corer, remove the center core in one smooth push, or cut around it carefully with a knife. This leaves you with a clean ring-shaped apple ready for slicing.
Lay the cored apple on its side and slice it crosswise into rings about a quarter-inch thick, or cut it into wedges if you prefer. I find rings easier for kids to hold, while wedges work better for dipping. Either way, aim for even thickness so every piece holds toppings well.
Take a spoonful of peanut butter and spread it generously over one side of each apple slice. I like to warm mine for about ten seconds in the microwave first, since it spreads much smoother that way and reaches every edge of the apple.
Sprinkle granola, dried cranberries, and sliced almonds over the peanut butter while it's still soft enough for them to stick. Gently press the toppings down with your fingers or the back of a spoon so nothing slides off when you pick it up.
Dust the assembled snacks lightly with cinnamon for extra warmth and flavor. Arrange them on a plate in a circle or a neat row, and serve immediately while the apple is still crisp and fresh.