Preheat the oven to 350 degrees. Sift the flour and baking powder into a medium bowl, set aside. If you don’t know what sifting is, it’s basically putting the ingredients through a tiny mesh strainer to get out any of the lumps and clumps.
In a large bowl, cream the butter and the sugar (basically beat the butter with a mixer on low and start adding the sugar gradually until its incorporated and fluffy).
Once the creamed butter is fluffy, add the vanilla extract and eggs (one at a time) and beat with a hand mixer.
When the eggs are all combined, slowly add the flour mixture a couple of tablespoons at a time and beat it all together. When it’s all mixed together, pour it into a 13×9, greased, baking pan. The batter may be thick, that is okay!
Bake for 30 minutes. When the cake comes out, let it cool for a few minutes and then poke holes all over the top of it with a fork.
Combine your three milks and then pour it over the cake a little at a time until it’s all completely absorbed. Place it in the refrigerator for 2 hours.
After two hours, you are ready to frost! Simply beat the heavy cream with the sugar on high until thick and spreadable (takes about 3 minutes). Spread it on the cake and top with cinnamon! Store in the fridge for up to 3 days.