Let’s break down the process into easy-to-follow steps.

Step 1: Prepare Oven and Pan. Preheat oven to 350°F (175°C). Butter a 9-inch deep-dish pie plate.

Step 2: Whisk Dry Ingredients. Stir together the flour, cornmeal, baking powder, baking soda, and salt in a medium bowl. Set aside.

Step 3: Combine Wet Ingredients. Beat 1/2 cup butter and brown sugar until fluffy, about 3 minutes. Add the egg and vanilla, and beat until just combined.

Step 4: Alternate Wet and Dry. Add half of the flour mixture, the buttermilk, then the remaining flour, beating until combined after each addition.

Step 5: Assemble and Bake. Spoon the batter into the prepared pie plate; spread in an even layer using the back of a spoon or a spatula. Scatter the berries evenly over the top of the batter; do not press them down. Sprinkle the berries and batter with 2 tablespoons turbinado sugar, if using.

Step 6: Bake. Bake until the top is golden brown and a wooden pick inserted into the cake (not a strawberry!) comes out clean, 40 to 45 minutes.

Step 7: Cool and Serve. Let cool before dusting with powdered sugar and serving with more sliced strawberries, if you like.

These instructions are clear.