Cinnamon Streusel Orange Muffins

Step 1
Preheat the oven to 350 degrees F (175 degrees C). Grease a 12 cup muffin tin, or line with paper liners.

Step 2
In a medium bowl, stir together 2 cups flour, 3/4 cup white sugar, baking powder and salt. In a separate bowl, whisk together the vegetable oil, orange juice, buttermilk, vanilla, and eggs. Pour the wet ingredients into the dry, and mix until just blended. Some lumps are okay.

Step 3
Fill the prepared muffin cups halfway with the batter. Combine the brown sugar, and 1 1/2 teaspoons cinnamon; sprinkle about 1/2 teaspoon of the mixture onto each half-full muffin cup. Spoon batter over the cinnamon mixture so that the muffin cups are 2/3 full. In a small bowl, mix together the remaining 1/4 cup flour, 1/4 cup white sugar, 1 1/2 teaspoons cinnamon, and the butter to make a crumbly mixture. Sprinkle this generously over the tops of the muffin batter.

Step 4
Bake for 20 to 22 minutes in the preheated oven, until a toothpick inserted into the crown of a muffin, comes out clean. Cool in the pan, over a wire rack.