Using a handheld mixer, or a stand mixer if you like, beat the butter and sugar together until creamy. (It takes a couple of minutes.)
Add eggs one at a time, mixing well between each one. Add the vanilla and mix well.
Add the flour, sugar, and baking soda to a separate bowl, whisking to combine.
Add the flour mixture into the butter mixture, stirring just until they are combined.
Spread on to the cookie sheet. You'll need to use your fingers--it's a thick dough, and you probably won't be able to use a spoon to do it very well. Press the dough into all the corners, and pat it down so that it's even across the cookie sheet.
Bake for 14-17 minutes, or until done. They shouldn't look wet in the middle, but should be pale in color. They'll look a little puffy, and barely golden brown around the edges. You don't want to overbake them!
After the bars have cooled, frost with Cream Cheese Frosting.
Cream Cheese Frosting
With a hand mixer (or stand mixer), combine the cream cheese and butter until creamy, and there are no little lumps. Making sure that both of them are completely softened first will help!
Add the vanilla and salt, then mix well.
Carefully and slowly add the powdered sugar until completely combined.