Cajeta is a Mexican caramel sauce that is made of sweetened goat's milk that is simmered until it thickens and caramelizes. This makes a perfect topping for any dessert!
In a large pot, stir together milk, sugar, cinnamon stick, salt, and vanilla. Bring to a boil over medium heat, stirring often.
Remove from heat and stir in baking soda.
Lower heat and simmer mixture to a gentle simmer. Stir every 10 minutes for about 1.5 hours, until it turns a light golden brown colour. Remove cinnamon stick and stir occasionally until mixture has thickened and coasts the back of the spoon.
Allow mixture to cool and store in airtight container. This will keep for 1 week refrigerated.