Cut off the top of the apples (about 1/8 to 1/4 inch) to make a flat surface. Flip the apples over.

Using a small paring knife, cut around the core of the apple, being careful not to cut all the way through to the bottom, then scoop out the core using a grapefruit spoon or melon baller.

Arrange the apples in a baking dish and put 2 tablespoons of water in the bottom of the dish. Put 1 teaspoon of orange juice into each apple.

For the streusel filling, stir the chopped pecans, rolled oats, brown sugar, raisins, cinnamon, and nutmeg in a bowl. Add the butter and orange zest and mix with your fingers, rubbing the butter into the dry ingredients until everything is evenly combined.

Divide the mixture evenly between the four apples. Press the mixture down into the cavities and then allow it to mound on top.

Bake for 30 minutes on the center rack.

Garnish with cinnamon sugar mixture and top with a pecan half.

Serve warm.