Preheat the oven to 375 F.
1. Wash strawberries, remove hulls, and slice in half lengthwise. Place in a small baking dish.
2. Drizzle with maple syrup, olive oil, and salt. Roast in the oven until soft and falling apart, about 30 minutes.
3. Add balsamic and toss to coat. Allow to cool while you make the streusel & cake.
Combine dry ingredients in a small bowl. Cut in cold butter until mixture resembles coarse crumbs. Keep chilled until ready to use.
Turn oven down to 350 F.
1. In a 9" cast iron skillet, melt the butter and allow to cool slightly.
2. In a medium bowl, whisk together sugar, flours, baking powder, and salt. Add melted butter, eggs, milk, and vanilla. Whisk just until combined.
3. Use your fingers or a paper towel to smear remnant melted butter evenly into cast iron skillet. Pour cake batter in. Dollop roasted strawberries on top, distributing carefully in a thin layer. Crumble streusel over cake.
4. Bake until toothpick inserted in middle comes out clean and cake and streusel are golden brown, about 35-40 minutes.
5. Place on a cooling rack and allow to cool.
Great eaten while still warm or at room temperature. Serve with whipped cream or vanilla sauce, is desired.
