Preheat oven to 350 degrees. Grease or line muffin tin.
In a large mixing bowl, combine butter, oil and sugar and add the eggs, vanilla and buttermilk until combined on low or by hand.
In a bowl, combine flour, baking powder, corn starch and salt.
Gradually fold dry ingredients into wet mixture, but do not overmix.
Fold in the chocolate chips
Fill 3/4 full and sprinkle with sugar.
Bake 18 minutes or until they pass the toothpick test.
This recipe makes 10 standard size muffins rather than 12.
Butter - Salted or unsalted, your preference.
Vegetable Oil - Vegetable oil works best, but you can substitute canola oil.
Vanilla Extract - Substitute Almond Extract if you prefer.
Buttermilk - Don't have any? You can make your own Buttermilk with milk and lemon juice.
Salt - Omit if using salted butter.
Chocolate Chips - I use semi-sweet, but you can use your favorite...anything goes! Milk chocolate, dark chocolate, even white chocolate chips!
Optional Add Ins
Add Nuts - Almonds, walnuts, pecans, oh my!
Add Zest - Orange zest goes so well with chocolate chips! You can even add a little orange extract.
Add Glaze - Drizzle a little glaze on top for an extra sweet treat.
How Do You Know When Muffins Are Done?
These muffins will take around 18 minutes to bake. You can check for doneness by lightly touching the top a muffin, it should spring back to shape. You can also insert a toothpick, if it comes out clean then they are ready. Because some ovens run hotter (and cooler!) it's best to check your muffins a couple of minutes before they are due to be ready.
Consistent Muffin Size
Use a cookie or ice cream scoop to get 10 picture perfect muffins. This keeps them consistent in size.
Top With Chocolate Chips
Save a few chocolate chips to sprinkle on top to make them look bakery made.
Room Temperature - Once you have baked these cookies, let them cool to room temperature and store them in an airtight container. Place a paper towel underneath and on top of the cookies to absorb any moisture and they will keep for 4 to 5 days.
Refrigerate - Allow to cool. Cover refrigerated up to 1 week.
Freeze - Wrap them individually to freeze up to three months. Thaw them at room temperature for 3 to 4 hours. If you like them warm, place them in a pre-heated oven at 350ºf for 3 minutes.