Preheat oven to 350°F (175°C). Grease and flour a 9-inch round cake pan.
In a large bowl, cream together butter and sugar until light and fluffy. Beat in eggs, one at a time, then stir in vanilla.
Combine flour, baking powder, and salt; stir into the creamed mixture alternately with the milk, mixing just until incorporated.
Fold in walnuts. Pour batter into prepared pan.
Bake for 30 to 35 minutes, or until a toothpick inserted into the center of the cake comes out clean. Cool for 10 minutes before inverting onto a wire rack to cool completely.
Interesting Facts
The Minnehaha Cake originates from the United States in the late 19th century.
The cake is named after the Minnehaha Falls in Minneapolis, Minnesota.
The cake is very popular in the Midwest, and is often served at family gatherings.