Cajeta (Mexican Caramel Sauce)

Stir together the milk and sugar in a large, heavy-bottomed pot. (Make sure the liquid only goes three fourths the way up the sides, as it will froth when the baking soda is added.) Add the cinnamon stick, salt, vanilla extract and vanilla bean seeds plus the empty vanilla bean pods. Bring to a boil on medium-high heat while constantly stirring. This will take about 15 minutes. DO NOT take your eyes off the pot. It boils over easily and quickly!

When the milk comes to a boil, quickly remove from heat and add baking soda to the pot. The mixture will rise and get frothy, just keep stirring the mixture.

Place the pot back on the stove over medium heat, and stir frequently, about every 10 minutes or so. Make sure the milk stays at a gentle simmer rather than a raging boil, and stir across the bottom of the pot to make sure the mixture is not scorching. Adjust heat as needed.

After about an hour and a half, the milk should start to turn golden brown. Remove the cinnamon stick and the vanilla pod. At this point, it will start to thicken fast, so it’s important to keep stirring so the milk doesn’t burn on the bottom of the pan.

Keep stirring until the mixture is a rich brown and thick enough to coat the back of the spoon, this will happen after about 15 to 30 minutes. Allow the sauce to cool slightly and then pour into airtight containers. The mixture will keep in the refrigerator for up to 1 week.