Preheat oven to 350°F and prepare muffin pans with paper liners.

Peel, core, and dice the apples into small pieces around a 1/4 of an inch or smaller.

Whisk or sift flour, salt, baking soda, and cinnamon in a medium bowl.

In a separate bowl, mix eggs, oil, sugar, and vanilla until completely combined and smooth.

Slowly beat the flour into the wet mixture while adding the water gradually. The batter will be fairly thick. Once thoroughly combined, mix in the apples.

Fill paper muffin liners 3/4 full and sprinkle each with a little brown sugar. Bake for 20-25 minutes until tops are crunchy and muffins are cooked through.