1. Use dulce de leche for a thicker less runny filling 2. freeze cupcakes 10 minutes before coring for cleaner holes 3. add 1 to 2 tsp espresso powder to intensify chocolate flavor 4. swap buttermilk with 0.5 cup milk plus 1.5 tsp lemon juice rested 5 minutes 5. store airtight at room temperature 1 day or refrigerate up to 4 days and bring to room temperature before serving