Prep the apples. Wash and dry the apples. Slice each one in half through the core.
Use a spoon or melon baller to scoop out the seeds and create a small well in the center. Brush the cut surfaces with lemon juice to slow browning.
Mix the filling. In a small bowl, stir together the almond butter, honey or maple syrup, cinnamon, salt, and vanilla if using. The texture should be thick but spreadable.
If it’s too stiff, add a teaspoon of warm water or a bit more syrup to loosen it.
Add crunch and extras. Fold in chopped nuts or seeds. If you like a hint of sweetness, mix in raisins. For a dessert vibe, add mini dark chocolate chips.
Stuff the apples. Spoon the almond butter mixture into each apple half, mounding slightly.
Press gently so it adheres to the fruit.
Finish with a sprinkle. Dust the tops with a pinch of extra cinnamon. Add a few more chopped nuts for texture.
Serve now or chill. Eat right away for the best crunch. If you prefer a firmer filling, chill for 15–20 minutes so the almond butter sets slightly.