Preheat your oven to 350°F (175°C). Grease and flour a 9-inch cake pan.
In a mixing bowl, whisk together the flour, cornmeal, baking powder, and salt.
In another bowl, combine the sugar, melted butter, eggs, buttermilk, and vanilla extract. Mix well.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Gently fold in the raspberries.
Pour the batter into the prepared cake pan and smooth the top.
Bake for 45 minutes, or until a toothpick inserted into the center comes out clean.
Let the cake cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.