1. Heat the oven and prepare the dish

Preheat the oven to 375°F with a rack near the center. Lightly grease the baking dish.

Arrange the whole apples in the dish briefly to confirm they fit upright with some room around them. Remove them for cutting.

Prepare the cinnamon butter ingredients before slicing so the cut fruit does not wait unnecessarily on the counter.

2. Core carefully from the top

Wash and dry the apples. Remove the stem and use a melon baller or small spoon to scoop out the seed core from the top.

Leave the bottom intact. Check the cavity as you work rather than driving an apple corer all the way through, which would create a hole for the filling to escape.

Remove seeds and tough core material while keeping a reasonable wall of fruit around the center. A very wide hollow can make the sections fragile.

3. Create connected petals

Set the apple upright on its natural bottom, with the opening facing up. Make evenly spaced radial cuts through the upper fruit, working outward from the hollow center and stopping about half an inch above the base.

Aim for roughly eight to twelve connected sections, depending on apple size and how comfortably you can cut. Keep your fingers away from the blade path and rotate the fruit carefully between cuts.

Do not cut completely through the bottom. The goal is a connected apple that can open as it softens, not separate wedges.

Gently test the sections with your fingers, but do not pry hard. Raw firm apple may not fan widely, and forcing it can snap the base. The oven will do much of the softening.

4. Mix the cinnamon butter

Whisk the melted butter, packed brown sugar, cinnamon, nutmeg, vanilla, and tablespoon of lemon juice together.

Stir again just before filling if the mixture separates slightly. A little graininess from sugar is normal at this stage.

Do not heat it into a candy mixture. It only needs to be combined and fluid enough to brush between the cuts.

5. Fill and coat

Place the apples upright in the prepared dish. Divide the cinnamon butter among them, spooning a little into each center and brushing some over the tops and into accessible cuts.

Use gentle pressure to open a gap only as far as the fruit allows. Do not try to fill every cut by forcing a stiff section sideways.

If a little mixture runs into the dish, leave it there for basting. The baking juices are part of the finished sauce.

6. Add the nuts

Divide the chopped pecans or walnuts among the centers and a few gaps. Scatter lightly rather than packing the cavities tightly.

Add the optional granulated sugar if desired. It increases sweetness and can encourage surface browning, but the dessert already contains brown sugar and caramel.

7. Bake covered first

Cover the dish loosely with foil and bake for about twenty minutes. The covered stage helps the apples begin softening without exposing the tops to the full drying heat throughout.

Remove the foil carefully, directing escaping steam away from your hands and face. Check the apples before continuing uncovered.

8. Finish uncovered and baste

Bake uncovered for another fifteen to twenty minutes as an initial guide. Spoon some of the warm juices over the apples during this stage.

Check tenderness with a small knife or skewer in a thick section near the center. The fruit should yield to your preference without the base falling apart.

Larger or firmer apples may need additional time, sometimes considerably more than forty minutes total. If the tops or nuts are darkening before the center softens, loosely cover again and continue.

If the dish is becoming dry before the apples are ready, add a small splash of hot water only if suitable for your baking dish and its manufacturer guidance. Avoid sudden temperature changes with glass dishes.

9. Encourage the bloom gently

Once softened, the sections may relax outward on their own. If needed, use a spoon to ease them apart very gently while keeping the base supported.

Do not try to create a wide flower by pulling on hot, fragile wedges. A partially opened apple is still attractive and easier to transfer intact.

10. Rest and finish

Remove the dish from the oven and let stand for at least five minutes. Check that the filling has cooled enough to serve comfortably; dense centers can retain heat longer.

Drizzle the two tablespoons caramel sauce across the four apples. Add a tiny pinch of flaky salt if desired.

Lift each apple with support beneath its base and place in a dessert bowl. Spoon some baking juices around it and add ice cream or whipped cream just before serving.