Preheat oven to 350. Grease cupcake tins. Sprinkle a teaspoon of brown sugar into the bottom of each cup, then arrange 4-5 strawberry slices on top. Reserve extra berries and sugar.
In a large bowl, cream butter and raw sugar until light and fluffy. Add eggs one at a time, beating well after each. Mix together flour, baking powder, and salt in a small bowl. In another, whisk together milk and both vanillas. (I just use a liquid measuring cup.)
Alternate adding flour and milk mixtures to the large bowl, starting and ending with the flour. Make sure everything is well combined, but don't overmix.
Divide batter equally between cupcake wells. Bake for 20-30 minutes, or until a toothpick inserted in center is clean. Cool for 5-10 minutes, then invert onto a cookie sheet. Carefully replace any strawberries that didn't stick to the cakes.
While cakes are baking, cook the reserved berries and brown sugar over medium-low heat, until thick and jam-like.
Cut the rounded tops off the cakes so each cake can sit flat. Add a spoonful of the cooked berries to the top of each cake and serve.