Rinse the whole fresh tejocotes. Cover with water in a medium saucepan, bring to a boil and simmer about 5 minutes, until the skins loosen. Drain and cool about 10 minutes, until safe to handle. Peel, halve and carefully remove every hard seed and the firm central core with a paring knife and teaspoon. If too firm to cut safely, blanch a little longer first. Weigh 600 g prepared fruit; blanch more if needed. Discard the blanching water, skins and seeds.

Put the measured 500 ml water, chopped piloncillo, cinnamon and star anise in a wide 2-quart saucepan. Heat gently, stirring until the sugar dissolves. Skim out any pieces of debris from the unrefined sugar.

Add the prepared fruit. Bring to a gentle simmer and cook uncovered about 20–30 minutes, turning carefully, until a fork enters the flesh easily while the halves retain their shape. Keep the fruit mostly bathed in syrup; add a small splash of hot water if the pan begins to dry. Time depends on the fruit.

Remove whole spices. The syrup should lightly coat a spoon and remain pourable; it thickens as it cools. If the fruit is tender before the syrup is ready, lift the fruit out and simmer the syrup alone for 3–5 minutes, then return it. Loosen overly thick syrup with a little hot water. Let settle and divide fruit and syrup into 6 portions. Serve warm or chilled, with optional yogurt or ice cream excluded from the estimates.

Transfer leftovers to shallow covered containers and refrigerate at 40°F (4°C) or below within 2 hours, or 1 hour above 90°F (32°C). Use within 3 days. This is a refrigerator dessert, not a tested shelf-stable canning recipe.