In a large bowl, combine the flour, sugar, baking powder and salt. In a small bowl, beat the egg, milk and oil. Stir into dry ingredients just until combined. Do not overmix. Fold in the cinnamon chips.
Fill 6 greased or paper-lined jumbo muffin cups three-fourths full.
For the topping, mix together the flour, sugar and cinnamon in a bowl. Mix in the butter until the mixture is crumbly. Divide the streusel evenly over the top of the muffins.
Bake at 375 degrees for 25 minutes or the top of the muffin bounces back when you touch it. Cool for 5 minutes before removing to a wire rack to cool completely.
If you'd like to make regular muffins, bake them at 400 degrees for 18-20 minutes or until they test done.