Preheat oven to 350 degrees. Cream the butter and sugar on medium speed for 3-5 minutes. Meanwhile, in a separate bowl, whisk together the flour, baking powder and salt. Set aside. Measure out 1/2 cup mini chocolate chips and stir with just enough of the flour mixture (about 1/2 tbsp) to coat the chips. To the butter and sugar, slowly add the maple syrup, vanilla, eggs, and milk, beating well after each addition until well combined. Add in the flour mixture 1/2 cup at a time and mix until just combined. Stir in the chocolate chips. Line a mini muffin tin with cupcake liners and fill the liners 3/4 full of batter. Bake at 350 for 7-9 mins, until a toothpick inserted into the center of the cupcake comes out clean.