Spray generously a 8 or 9” round baking dish.

Purée apple, cranberries, 1½ cups sugar, and 1 cup water in a blender until smooth.

Transfer to a large deep heavy pot fitted with thermometer and cook over medium heat, whisking pretty frequently.

The mixture will become pretty thick and bubbly (it will splatter a ton while it cooks), about 8–10 minutes.

Whisk pectin and remaining ½ cup sugar in a small bowl, then gradually whisk into cranberry mixture.

Reduce heat to medium-low and continue to cook, whisking often, until thermometer registers 200°, 15–20 minutes (The mixture will become dark red and pretty thick).

Whisk lemon juice into cranberry mixture.

Pour into prepared dish with a spatula; smooth the top before you let it set.

Let cool until set (I put it in the fridge but you do not have too), at least 4 hours.

Before serving, take jelly out of the dish and cut into 1” squares.

Finish by filling a plate with the remaining sugar.

Roll the jellies in sugar to coat.

Serve and enjoy!