Apple and cinnamon muffin

This recipe has a special flavor: it was the first request made by a dear follower and friend, and it was prepared with the attentive eye of my talented mother, who is an expert in cakes!

Ingredients
1 cup all-purpose flour
1/2 cup whole wheat flour
3/4 cup brown sugar
1 pinch of salt
2 teaspoons baking powder
1 teaspoon ground cinnamon
1/3 cup canola oil
1 egg
1/3 cup milk
2 peeled and chopped apples
Topping Ingredients
2 tablespoons brown sugar
1 tablespoon all-purpose flour
1 tablespoon butter, diced
1 teaspoon ground cinnamon

Instructions
Preheat the oven to 200ºC (400ºF). Grease and flour 6 muffin pans.
In a bowl, mix the flours, sugar, salt, baking powder, and ground cinnamon. Add the oil, egg, and milk. Mix well until you have a homogeneous batter. Add the chopped apples.
Distribute the batter into the muffin pans using a spoon.
In a small bowl, use a fork to mix the topping ingredients. Spread the topping over the muffins.
Bake for 25 minutes. Perform the toothpick test by inserting it into the center of a muffin. If it comes out clean, they're ready.