Apple Pie Muffins

Ingredients
Topping
1/2 cup firmly packed brown sugar
1/3 cup all-purpose flour
1/4 cup unsalted butter, melted
1 teaspoon cinnamon

Muffins
1 1/2 cups firmly packed brown sugar
2/3 cup vegetable oil
1 egg
1 1/2 teaspoons vanilla
2 1/2 cups all-purpose flour
1 teaspoon baking soda
1/4 teaspoon salt
1 cup buttermilk
2 cups diced peeled firm tart apples (such as Granny Smith)

Directions

1. Note: cinnamon could be added to the batter ( about 1 teaspoon or less). 
2. Topping: In a small bowl toss together sugar, flour, butter and cinnamon until crumbly; set aside. 
3. Muffins: In a large bowl whisk together brown sugar, oil, egg and vanilla until smooth. 
4. In a separate bowl, sift together flour, soda and salt. 
5. Stir oil mixture into flour mixture alternately with buttermilk. 
6. Fold in apples, mixing just until combined. 
7. Spoon into greased muffin cups filling 3/4 full. 
8. Sprinkle topping over evenly. 
9. Bake at 350°F for 25-30 minutes or until golden brown and tops spring back.

Notes: I have a bad habit of checking the ingredient list to see if I have everything, but not checking the actual amounts of each ingredient. This recipe has way more sugar than other muffin recipes I've made. I didn't notice until I had already started making it, though, and I was too tired to think about making adjustments so I just followed the recipe. The result was tasty but very sweet - enough so that no one wanted to eat more than one (unusual with my family and muffins). If I make these again I will reduce the sugar in the muffins to 1/2 cup or eliminate it entirely since the topping is sweet. Having said all that, I am craving these right now as I type this up. 

Source: Food.com