Homemade Dulce de Leche

If using classic method: Stir together 4 cups whole milk, 1¼ cups (250 g) granulated sugar, and ¼ tsp. baking soda in a 3–4-qt. heavy saucepan. Bring to a boil, then reduce heat and simmer uncovered, stirring occasionally, until caramelized and thickened, about 1½–1¾ hours. (After about 1 hour, stir more frequently as milk caramelizes to avoid burning.) Remove from heat and stir in 1 tsp. vanilla extract. Transfer to a bowl to cool. Makes about 1½ cups If using boiling method: Place one 14-oz. can sweetened condensed milk (unopened, label removed) on its side in a large pot; pour in room-temperature water to cover by at least 2". Bring to a simmer over medium-high heat. Reduce stove to low heat, partially cover, and simmer, adding water as needed to maintain water level, 3 hours. Let can cool still submerged in water, 40–60 minutes. Remove can from pot and continue to cool at least 3 hours before opening. (Do not open it before it is fully cooled.) Makes about 1¼ cups If using baking method: Place rack in center of oven; heat oven to 425°F. Pour the contents of one 14-oz. can sweetened condensed milk into a 9" deep pie dish and cover tightly with foil. Set dish in a roasting pan and add enough hot water to roasting pan to reach halfway up outside of pie dish. Bake for 45 minutes. Check water level, adding additional if necessary, then continue to bake until milk is thick and has reached a warm brown color, about 45 minutes longer. Remove pie dish from water bath and cool, uncovered. Stir vigorously before serving. Makes about 1¼ cups