Halve the pineapple lengthwise, right through the crown, keeping it attached. Put both halves cut-side up in front of you. On one of the halves, use a small sharp knife to cut into and around the perimeter of the fruit about 1/4 inch in from the peel. Locate the core in the center: cut it out on an angle on either side (it will look like a long V) and discard. Cut the remaining pineapple into a grid of small squares. Use a spoon to scoop the pieces out, leaving the pineapple empty. Chop any large pieces a little smaller and set aside in a bowl. Repeat with the other pineapple half, but reserve the pieces of fruit for another use.
Whisk together the eggs and a small pinch of salt in a small bowl. Heat 1 teaspoon of the oil in a large nonstick skillet over medium-high heat. Pour the eggs into the skillet and let them run freely until they cover most of the bottom. Cook, undisturbed, until the top is set and no longer runny, 4 to 5 minutes. Roll up into a cylinder and transfer to a cutting board. Cut into thin spiral slices.
Return the skillet to high heat and add 2 tablespoons oil. Once the oil just begins to smoke, add the ham, sugar, garlic, ginger, scallion whites and 1 teaspoon of the soy sauce and cook, stirring constantly, until the ham is browned, about 2 minutes. Add the rice, pepper and remaining 3 tablespoons soy sauce and cook, stirring occasionally, until the rice is heated through and the pepper is crisp-tender, about 3 minutes. Stir in the pineapple pieces, cooked egg, most of the peanuts and scallion greens, the remaining 2 teaspoons oil and salt to taste.
Fill each pineapple half with the fried rice. Sprinkle with the remaining peanuts and scallion greens.