Conchas (Mexican Sweet Bread)

Before you start

Conchas are the round sweet rolls stacked in every Mexican panadería case, named for the seashell pattern pressed into their sugary crust. Underneath is a plush, lightly sweet dough enriched with eggs, milk and butter; on top is a paste of flour, powdered sugar and fat that bakes into a thin layer that cracks along the scored lines.

The two parts behave differently, so treat them separately. The dough needs a slow, full rise and a gentle hand when shaping so the buns stay tall. The topping should feel like soft cookie dough: too wet and it slides off in the oven, too dry and it flakes away before baking. Press it on firmly, score it with a light touch, and bake at a moderate heat so the shell stays pale while the bun underneath turns golden.

Ingredients

• Dough375 g (3 cups) bread flour — or all-purpose flour for a softer, slightly flatter bun
• 75 g (6 tbsp) granulated sugar
• 7 g (2¼ tsp) instant yeast
• 1 tsp (6 g) fine salt
• 2 large (about 100 g) eggs — room temperature
• 120 ml (½ cup) whole milk — warmed to about 35°C (95°F)
• 1 tsp vanilla extract
• 85 g (6 tbsp) unsalted butter — very soft
• Shell topping60 g (½ cup) all-purpose flour
• 60 g (½ cup) powdered sugar
• 55 g (¼ cup) vegetable shortening or soft unsalted butter — shortening keeps the topping whiter and less likely to spread
• ¼ tsp ground cinnamon — optional
• 2 tsp unsweetened cocoa powder — for a chocolate topping on half the buns

Method

1. Combine the bread flour, sugar, yeast and salt in the mixer bowl. Add the eggs, warm milk and vanilla and mix on low for 2 minutes until a shaggy, sticky dough forms.
2. Knead on medium-low for 5 minutes. Add the soft butter a spoonful at a time, letting each piece disappear before the next. Knead another 6 to 8 minutes, until the dough pulls away from the bowl and stretches thin without tearing quickly.
3. Shape the dough into a ball, place it in a lightly oiled bowl and cover. Let it rise at warm room temperature, about 24°C (75°F), for 1 to 1½ hours, until doubled.
4. Make the topping while the dough rises. Rub the flour, powdered sugar, shortening and cinnamon together with your fingers until it forms a smooth, pliable paste. Split it in half and knead the cocoa into one half.
5. Turn the dough out, press out the gas and divide it into 8 pieces of about 95 g. Round each into a taut ball by cupping your hand and rolling it against an unfloured counter. Set 4 on each baking sheet, well spaced.
6. Divide each topping into 4 balls of about 22 g. Flatten each between two sheets of plastic wrap into a 9 cm (3½ in) disc. Lay a disc on each bun and press gently so it hugs the dome and reaches about two-thirds of the way down the sides.
7. Score a shell or crosshatch pattern into the topping with the cutter or a knife, cutting through the paste but not into the dough. Cover loosely and proof for 45 to 60 minutes, until the buns look puffy and the score lines have opened.
8. Heat the oven to 180°C (350°F) during the last 20 minutes of proofing. Bake one sheet at a time on the middle rack for 18 to 20 minutes, until the sides are golden and the bottoms sound hollow; the topping should stay pale.
9. Cool the conchas on the sheet for 5 minutes, then move them to a rack for at least 15 minutes before serving.

Tips for success

• If the topping cracks when you flatten it, knead in a few drops of milk. If it sticks to the plastic, chill it for 10 minutes.
• Keep the scored lines shallow. A deep cut splits the dough and the bun bursts unevenly during baking.
• Weigh the dough pieces. Even buns bake at the same rate, so none brown before the others are done.

Substitutions

Vegetable shortening

Butter gives a richer, slightly yellow topping that tastes better but spreads more and cracks into smaller pieces. Chill the topped buns for 10 minutes before baking.

Bread flour

All-purpose flour gives a more tender, cake-like crumb but the buns spread a little wider. Hold back 10 ml of milk, since it absorbs slightly less.

Whole milk

Evaporated milk adds a deeper dairy flavor and browns faster; check the buns at 16 minutes.

Variations

Pink conchas

Knead a drop of red gel food coloring and ¼ tsp strawberry extract into half the topping in place of the cocoa.

Orange conchas

Add the finely grated zest of 1 orange to the dough with the eggs and to the plain topping.

Troubleshooting

Topping slid off during baking

The paste was too soft or not pressed onto the dough. Use the stated fat amount, chill warm topping before shaping, and press each disc down so it grips the sides of the bun.

Topping fell away in flakes after baking

It was too dry or too thin. Add a teaspoon of fat or milk to the paste and keep the discs about 3 mm thick.

Buns are dense and small

The dough was underproofed or the butter went in before the gluten developed. Knead until the dough is elastic before adding butter, and wait until the buns are clearly puffy before baking.

Shell browned before the bun cooked

The oven ran hot or the rack was too high. Bake at 180°C on the middle rack and lay a sheet of foil loosely on top for the final minutes if needed.

Storage

Conchas are best the day they are baked. Keep leftovers in a closed paper bag inside a plastic bag at room temperature for up to 2 days, and warm them for 5 minutes at 150°C (300°F). Freeze for up to 1 month, wrapped tightly.