Pre-heat oven to 350 F.
Sift baking powder, flour and salt; set aside.
Cream butter in the mixer bowl with paddle attachment till light and fluffy on speed #2, add sugar gradually until all the sugar is incorporated.
Lower the speed to #1 and start adding on egg at a time until blended. Continue to mix, adding vanilla. Scrape the sides of the bowl.
Add a third of the flour mixture to the batter and continue mixing; add1/2 of the milk, scrape the bowl and add another 1/3 of the flour mixture to the batter. Continue to mix, making sure to scrape the sides of the bowl. Add the remaining 1/2 of the milk; once incorporated, add the rest of the flour mixture and finish mixing, making sure all ingredients are well incorporated.
Pour the batter into an 8” buttered cake pan, lined with parchment paper.
Place in lower 3rd rack of preheated oven and bake for 55-70 minutes until the center of the cake springs back when touched and sides come apart from the pan.
Let cool completely.