Preheat the oven to 400℉ and line the muffin baking pan with parchment paper muffin cups. (I recommend parchment paper because it's easy to peel them off but you can use any muffin cup liners.)
Combine sugars and eggs in the mixing bowl and whisk vigorously for a few seconds, until light in color and fluffed.
Whisk in buttermilk, melted butter, and vanilla extract until combined.
Add flour, baking powder, baking soda, cinnamon, and salt and whisk until just incorporated. (Don't overmix!)
Fold in the cranberries and white chocolate chips until they're evenly spread throughout.
Use an ice cream scoop to get even amounts of batter and fill each muffin cup about 2/3 full.
Bake for 18-20 minutes.
Cool muffins on a wire rack.
Notes
Tips and Recommendations:
Don’t overmix the muffin batter or the muffins could deflate and come out dense and chewy.
Always check your baking powder and baking soda before baking, especially if you don’t bake often. Baking powder and baking soda should be used within 6 months after opening or they loose their potence and don’t work well.
Use an ice cream scoop to scoop the muffin batter into the cups so you get the same amount each time.
Feel free to play around and add some other mix-ins like nuts or fried berries.
To get a sweet crunchy top, feel free to sprinkle some sparkling sugar on top, before baking.