Step 1: Combine the Dry Ingredients.

In a medium bowl, stir together the flour, cornmeal, baking powder, baking soda, and salt.

Make sure the ingredients are well combined. This ensures that the leavening agents are evenly distributed.

Step 2: Prepare the Oven and Pan.

Preheat the oven to 350°F (175°C).

Butter a 9-inch deep-dish pie plate. This prevents the cake from sticking.

Step 3: Cream the Butter and Sugar.

In a separate large bowl, beat the 1/2 cup of softened butter and the brown sugar together until fluffy. This should take about 3 minutes.

Use an electric mixer for best results. The mixture should be light and airy.

Step 4: Add the Egg and Vanilla.

Add the egg and vanilla extract to the creamed butter and sugar.

Beat until just combined. Don’t overmix.

Step 5: Alternate Adding Dry Ingredients and Buttermilk.

Add half of the flour mixture to the wet ingredients.

Beat until just combined.

Add the buttermilk. Beat until just combined.

Add the remaining flour mixture. Beat until combined after each addition. Don’t overmix.

Step 6: Assemble the Cake.

Spoon the batter into the prepared pie plate.

Spread the batter in an even layer using the back of a spoon or a spatula.

Scatter the halved strawberries evenly over the top of the batter. Do not press them down.

Sprinkle the berries and batter with the turbinado sugar, if using.

Step 7: Bake the Cake.

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.

Baking time may vary depending on your oven. Start checking for doneness at 40 minutes.

Step 8: Cool and Serve.

Let the cake cool in the pie plate before dusting with powdered sugar.

Serve with more sliced strawberries, if desired.