Preheat the oven to 400F degrees. Prepare 12 standard-sized muffin cups – either grease the tins or use paper liners, and grease the liners (I use butter flavored vegetable spray.
For the topping: In a small bowl, stir together the 1/2 cup flour, 1/4 cup brown sugar, 1/2 teaspoon ground cinnamon, and a pinch of salt. Using your pastry blender, or a couple of butter knives, cut the butter into the mixture until the topping is the texture of coarse crumbs (butter should be about the size of small peas). Set this bowl aside.
In a larger bowl, combine the flour, brown sugar, baking powder, baking soda, cinnamon, and salt. Make a well in the center of this mixture and set aside
In another small bowl, whisk together the buttermilk, egg, oil and vanilla.
Stir the wet ingredients (not the topping ingredients!) into the dry ingredients just until combined~do not over mix! Batter will be thick. Fold in your 2 cups of strawberries.
Divide the batter between the muffin cups, filling a little over 3/4 full. Sprinkle topping over the top – it works out to about 1 1/2 tablespoons per muffin.
Bake for about 20 minutes until the topping turns golden brown and a toothpick inserted into the center of a muffin comes out clean.
Let cool for about five minutes, then remove muffins from the tins and place on a wire rack until cool enough to eat.
*NOTE: To make a buttermilk substitute, you can mix just under a cup of regular whole milk or evaporated milk with 1 tablespoon vinegar. Mix and let sit for about 10 minutes.