Preheat the oven to 325°F. Wash, core, and slice each of the strawberries in half.
In a well-seasoned, 10.5 inch cast iron skillet, heat 1/2 cup butter and the brown sugar over medium heat until butter is melted; stirring constantly. Remove from heat.
Arrange the strawberries in the skillet, carefully pressing them into the caramel mixture.
Melt the remaining 1/2 cup butter and add it to a large bowl with the cake mix, water, and eggs. Mix well.
Pour the cake batter over the strawberries.
Bake for 45 to 50 minutes or until a toothpick inserted in the center comes out clean.
Immediately cover pan with a platter and invert. Serve warm, topped with whipped cream, if desired.