Preheat oven to 350F°. Fill 12 cup muffin pan with liners. Mix flour, sugar, baking powder and salt together. Add in wet ingredients, combining well. Scrape the sides of the bowl often. How the rest goes depends on your plans.
Blueberry: skip cinnamon and add 2 cups blueberry to mixture.
Apple cinnamon: add cinnamon to mixture followed by 2 cups of chopped apples.
Apple cinnamon cranberry: add cinnamon to mixture followed by 1 - 1 1/2 cups of chopped apples and 1/2 - 1 cup dried cranberries.
Using a large cookie scoop, divide up batter between your 12 muffin liners. Top off with a spoon full of sugar. Pop in the oven for 25 minutes, cool at least partially before enjoying.