Dulce de Mostachón (Mexican Milk Candy with Pecans)

Instructions

1. Line a baking sheet with parchment and rub it lightly with a little of the unsalted butter.
2. In a wide, heavy 4-quart (4 L) pot, stir together the whole milk, granulated sugar and baking soda. Bring to a simmer over medium heat, stirring until the sugar dissolves; the milk will foam up briefly.
3. Lower the heat and keep at a gentle simmer, stirring every few minutes and scraping the bottom, until reduced by about two-thirds and thick like cajeta, about 1 hour. Keep the heat moderate so the mixture stays a pale tan rather than dark brown.
4. Clip on a candy thermometer and continue cooking, stirring constantly, until the mixture is very thick, leaves a trail when the spatula is drawn across the bottom and reads 236°F (113°C), 20 to 30 minutes more.
5. Take the pot off the heat, add the vanilla extract and beat hard with a wooden spoon until the candy thickens, loses its gloss and begins to hold its shape, 3 to 5 minutes.
6. Let it cool in the pot until you can handle it comfortably, 15 to 20 minutes. Butter your hands lightly with the rest of the butter.
7. Pinch off pieces about 1 tablespoon (15 g), roll each into a ball and flatten into a 1 1/2-inch (4 cm) patty on the prepared sheet. Press a pecan half into the top of each.
8. Let the candies set at room temperature until firm and dry on the surface, about 2 hours.