Preheat oven to 350 degrees Fahrenheit. Generously butter muffin tin. (Recipe makes 9 muffins.)
Quarter and slice strawberries and place in a medium bowl. Cover with 3 tablespoon sugar, 1 teaspoon lemon juice, ½ teaspoon vanilla and ⅛ teaspoon cinnamon. Toss and set aside.
Using a mixer, cream butter and sugar. Add egg and vanilla. Mix on low just until incorporated.
In a medium mixing bowl, mix together four and all dry ingredients.
With mixer on low, alternately add a little flour mixture and then buttermilk to creamed butter and sugar until all ingredients are incorporated. Batter will be thick like a dough.
Strain strawberries. In muffin tin, spoon 1 tablespoon of muffin dough into bottom of tin. Add one spoon of strawberries (4-5 slices). Press gently into dough. Add enough dough to cover top of strawberries without overfilling cup. Top with 4-5 more strawberry slices. Press gently into dough again.
Bake for 25 minutes or until golden brown. Tops should bloom out and slightly spread. Let muffins cool in tin for 5 minutes before removing.