Preheat oven to 350° and grease or spray a jumbo muffin pan with a non stick spray. Set aside.
In a medium mixing bowl, whisk flour, baking powder, baking soda and salt together.
In another medium mixing bowl, beat butter and sugar together until mix well. Add one egg at a time, beat until creamy then add vanilla and mix well.
Add dry ingredients into wet ingredients, stir. Fold in apples and pecans. Stir.
Spoon apple pecan mixture into prepared Texas size muffin pan.
In a small mixing bowl, stir brown sugar, flour, cinnamon and butter together until crumbly.
Sprinkle streusel topping on top of each muffin and pop in the oven for 30 minutes or until a tooth pick inserted comes out clean.
Serve warm: optional - smother in butter!
Recipe adapted from allrecipes,com