Step 1

Preheat the oven to 400 degrees F. Grease a 9-inch cake pan with non-stick cooking spray.

Step 2

In a medium bowl, combine the flour, baking powder, baking soda and salt.

Step 3

In a large bowl, cream the butter and 2/3 cup sugar with an electric mixer until light and fluffy, about 2 minutes. Beat in the egg and vanilla extract.

Step 4

On low speed, add the flour in 3 batches, alternating with the buttermilk. Mix until just combined.

Step 5

Transfer the batter to the prepared cake pan smoothing into an even layer. Place the raspberries on top and sprinkle with the remaining sugar.

Step 6

Bake the cake for 25-30 minutes until golden brown and a toothpick inserted into the center of the cake comes out clean. Cool the cake in the pan for 10 minutes before removing and cooling on a wire rack. Serve warm or at room temperature.