With the rack in the middle position, preheat oven to 350 °F (180 °C). With softened butter, butter a 20-cm (8-inch) square baking dish.
In a large bowl, combine the flour, sugar, baking powder, and salt. Add the remaining ingredients and combine using a whisk or an electric mixer until the batter is smooth. Pour the batter into the baking dish.
Bake the cake for about 55 minutes or until a toothpick inserted in the centre of the cake comes out clean. Let cool on a wire rack in the pan. Once cooled, ice the cake or simply cut into squares and serve with strawberries and whipped cream or ice cream.