Preheat the oven to 350 degrees F. Grease and flour a rectangular 9” x 13” cake pan.
In a large mixing bowl, sift the flour and baking powder together. Set aside.
Using an electric stand mixer on medium speed, cream the butter and 1 cup of sugar together until fluffy.
Add the eggs, one at a time, and beat thoroughly. Add the vanilla extract and mix well.
Add the flour mixture to the batter in small batches - one tablespoon at a time. Mix until well-blended. Stop to scrape down the sides of the bowl (to ensure all the flour gets evenly mixed with the batter.)
Pour the batter into the prepared pan, and bake at 350 degrees for 30 minutes.
Remove from oven and let cool. Pierce the top of the cake with a fork. (Poke the cake all over. This will make it easier for the milk cream to be absorbed into the cake.)