Preheat oven to 350°F and if using a regular mini muffin pan, grease each muffin section.
Beat together the sugar and butter. This works best if your butter is at room temperature. You can also melt the butter if needed.
Add in the pumpkin, eggs, vanilla, and milk, beating until these are mixed well.
Next mix in the baking powder, baking soda, salt, and both flours.
Fold in your mini chocolate chips and ground walnuts until well combined.
Using a scooper or a spoon, add roughly 1 tbsp of your mini pumpkin muffin batter to each muffin section, topping with a few mini chocolate chips as well. Push mini chocolate chips into the batter to ensure they stick and don't fall off.
Bake mini muffins for 15 to 18 minutes or until firm. Let cool before removing from muffin pan.
Notes
Add a little extra natural sweetness with one mashed banana and 1/2 the amount of pumpkin.