Position a rack in the middle of the oven and preheat to 350 degrees.

Cut the apples in half through the stem end, then use a melon baller or small spoon to remove the seeds and core each half. Remove a thin slice on the round side of each apple half so it can stand without wobbling. Place the apple halves, cored side up, into an 8-inch square baking dish.

Drizzle the top of each apple half with ¼ teaspoon of the oil, ½ teaspoon of the honey and sprinkle with the cinnamon. Add ¼ cup of the water to the bottom of the pan, being careful not to pour any on the apples, and transfer the pan to the oven. Bake for about 45 minutes, or until the apples can be easily pierced with the tip of a sharp paring knife.

Meanwhile, in a small, dry skillet over medium-high heat, toast the walnuts, stirring frequently, until fragrant and a shade darker, 3 to 4 minutes. Transfer the walnuts to a cutting board. Return the skillet to medium-high heat and add the sesame seeds. Toast, stirring frequently, until golden brown, 1 to 2 minutes. Transfer the sesame seeds to a small bowl.

Finely chop the walnuts and transfer to the bowl with the sesame seeds. Add 2 teaspoons of the honey and the salt, and stir to combine.

In another small bowl, stir together the tahini, the remaining 2 teaspoons of honey and 1 tablespoon of water until combined. Add more water as needed until the mixture is thin enough to drizzle.

To serve, place the apple halves on a serving plate, or divide among individual plates or bowls. Fill the cavity of each half with the walnut mixture, then drizzle with the tahini sauce.