Open the can of sweetened condensed milk.
Pour the condensed milk into a heavy-bottomed saucepan.
Add the baking soda, vanilla extract, and pinch of salt.
Stir the mixture well to combine all ingredients.
Place the saucepan over low to medium heat.
Cook, stirring constantly, for about 45 minutes to 1 hour.
Watch for a change in color to a golden brown.
Remove from heat once desired thickness is achieved.
Allow to cool, then transfer to a jar for storage.