Canadian Upside-Down Cake

Preheat the oven to 350 degrees F. Butter a 9-inch square baking pan.

Sift the flour, baking powder, cinnamon, and salt into a medium bowl. Beat the butter, sugar, and egg in a large bowl with an electric mixer at medium speed until creamy. With mixer at low speed, gradually beat in the dry ingredients, alternating with the milk.

Bring the maple syrup to a boil in a small saucepan over medium-low heat. Stir in the walnuts and remove from the heat. Pour the walnut syrup into the prepared pan. Spoon large dollops of the batter over the top. Use a thin metal spatula to spread the batter; it will soften with the heat of the syrup.

Bake for 25-35 minutes, or until a toothpick inserted into the center comes out clean. Cool the cake in the pan for 10 minutes. Turn out onto a serving plate. Serve warm.