Step 1
Preheat the oven to 350 degrees F (175 degrees C). Grease and flour a 9-inch square cake pan.

Step 2
Cream sugar and butter together in a mixing bowl. Add eggs, one at a time, beating briefly after each addition. Mix in vanilla.

Step 3
Combine flour and baking powder in a separate bowl. Add to the wet ingredients and mix well. Add milk and stir until smooth. Pour batter into the prepared cake pan.

Step 4
Bake in the preheated oven until the top springs back when lightly touched, 30 to 40 minutes.

Step 5
Remove from the oven and cool completely.