✓ In a medium microwave-safe bowl, add the semi-sweet chocolate chips and unsalted butter. Microwave on high for 30 seconds, then stir until smooth. If not fully melted, continue microwaving in 15-second intervals, stirring between each.

✓ Once the chocolate is completely melted, pour in the sweetened condensed milk and mix thoroughly to ensure all the ingredients are well incorporated.

✓ Stir in the vanilla extract next for added depth of flavor.

✓ If you find the mixture too thick, thin it out by adding a tablespoon or two of heavy cream or milk, stirring until smooth. For a thinner sauce, add more; for a thicker one, reduce the amount.

✓ Place the bowl over a pot of gently boiling water (a double boiler setup), ensuring the bottom of the bowl doesn’t touch the water. Cook the mixture, stirring occasionally, for about 5 minutes or until it thickens slightly and coats the back of a spoon.

✓ Once the sauce reaches your desired consistency, remove it from the heat source and let it cool to warm room temperature before serving.