In a 10 – inch cast iron skillet, stir together the blackberries, brown sugar, orange juice, vanilla extract, cardamom and orange peel over medium-high heat. Bring to a simmer, and cook until juice is released from blackberries and mixture is hot and bubbly, approximately 10 minutes.
In a small bowl, whisk together cornstarch and 3 tablespoons water. Slowly add to berry mixture, stirring to combine. Cook until thickened, about 3 minutes. Remove from heat.
In a medium bowl whisk together flour, sugar, baking powder and salt. Add butter. Combine with fingertips until crumbly. Add cream and stir gently until biscuit like dough forms.
Tear dough into 3-inch round pieces: arrange over berries. Sprinkle with sanding sugar.
Bake until topping is lightly browned, 30 minutes.
Notes
PRO TIPS
I strongly recommend using a baking sheet under your skillet. The fruits will cook in the oven and bubble over, so if you do not want to clean a sticky mess for days, you can use something under your skillet to catch it all.
Frozen blackberries work well with this recipe, be sure to add them at the last minute. Once thawed, they will become mushy during the cooking and baking process, and you will not have that beautiful berry consistency.
Use the butter chilled with your flour to produce the best topping. Melted butter will render the dough too thick and prevent it from rising and becoming flaky.