Rustic Plum Biscuit Pie

2 lbs ripe plumbs, pitted and quartered
1/2 cup granulated sugar
1/2 cup all-purpose flour
1 teaspoon ground cinnamon
1 3/4 cups all-purpose flour
1/3 cup fine yellow cornmeal
1/3 cup granulated sugar
2 teaspoons baking powder
1/2 teaspoon salt
1 1/2 sticks (12 tbsp) cold unsalted butter, cut into 12 pieces
1 cup cold heavy whipping cream

How to Make Rustic Plum Pie Filling:
Mix together 1/2 cup of sugar, 1/2 cup flour and 1 tsp of cinnamon.
Rinse plums, cut them into quarters and remove pits. Transfer half of your plums to a deep pie pan. Sprinkle half of your sugar/flour/cinnamon mixture over the plums.
Add remaining plums and sprinkle with remaining flour mixture.
How to Make the Biscuit Topping:
Place the first 5 topping ingredients in the bowl of a food processor: 1 3/4 cups flour, 1/3 cup cornmeal, 1/3 cup sugar, 2 tsp baking powder, 1/2 tsp salt. Pulse to combine.
Add sliced butter and pulse until pea-sized crumbles form.
Drizzle with heavy cream and pulse until just combined. Place large spoonfuls of dough (I used an ice cream scoop) evenly over the border of the pie, leaving a space in the center (this space helps to vent the pie and gives the pie more of a rustic look).
Bake in the center of the oven at 375 for 40-45 minutes or until top is golden and liquid is bubbling. Place a sheet of foil or baking sheet on the rack below your pie for the last 20 minutes to catch any juices that bubble over.