You won't get a buttery taste from adding butter to the dough. Even in fat-rich batters like pound cake, the difference between butter and a neutral fat is subtle - it is there, but it doesn't taste like biting into a buttered toast. And in a pizza, you can't add such amounts of fat to the dough, because it will interfere with gluten production, resulting in the wrong dough texture.
If you are prebaking the pure base at some point, putting butter on top of it will give you some buttery taste. But most pizza recipes call for immediate baking with the sauce, if not toppings, without prebaking the naked base (the exception is made for baking thick-crusted pizza in a regular, low-temp oven).
Putting butter in the sauce is also an option, but it will tend to be quite overwhelmed by the tomatoes. In general, a sour taste masks fats well, and a tomato sauce is sour.
I think that your best bet is to use some toppings which remain above the cheese, and put pieces of butter on them the moment you get the pizza outside, or, if they are crustable, in the last 5 minutes of baking. This will create small patches of melted butter with a distinctive flavour. If you do it on the cheese, it will mix with the cheese fat, and make it too greasy, so toppings above the cheese should function better.
The last option is to cheat and use butter aroma - this is what many commercial bread producers use. I wouldn't do that, because I am able to distinguish it for the real thing, but many people seem to be happy with it.
There are many cookies which are made via the creaming method, as it helps these cookies achieve the proper texture and leavening.
It is far from the exclusive method for cookies; there are many cookies which are made by alternate methods.
Many cookies, for example, are made with melted butter which does not have the ability to trap air the way solid butter or shortening does.
There are other cookies, such as French macarons, which have their structure and leavening from egg whites.
Best Answer
As Jason Sandeman already said in his answer, adding the butter to mixed dry ingredients (including things other than sugar) is called the "two step" or "two stage" method. Many professional bakers recently have advocated using it to produce more a more tender crumb with a velvety consistency.
In terms of food science, the difference is primarily due to gluten production. In a typical creaming method recipe, the butter and sugar are combined to create bubbles, and those bubbles are stabilized by alternating additions of flour and liquid, which form gluten strands to support the bubbles. The cake rises high due to big bubbles and a support structure.
When the flour is combined with the fat first, the fat envelops many of the flour particles, inhibiting their ability to interact with liquid when added later. Thus, less gluten is formed. Bubble formation is also inhibited somewhat (and bubbles are smaller sized). That means an exceptionally tender cake with a fine crumb, but which won't rise quite as high or be as "light."
The reason it's called the "two stage" method is to differentiate it from a "single stage" mix (or a "quick mix"), where all ingredients are just thrown together, as in a boxed cake mix. (I believe the "two stage" method was originally developed in the 1940s or 50s, when boxed mixes were first becoming popular.) The problem with the "single stage" method is that it will fail with "high ratio" cakes, i.e., those having a significant amount of sugar compared to flour. In that case, a "single stage" mix won't allow the moisture to dissolve the sugar granules fully, resulting in a somewhat "crunchy" or "mealy" sugary texture (like a sugar cookie).
If you don't want your financiers to taste like a sugar cookie, you need to dissolve the sugar thoroughly. And if you value tenderness over lightness, try adding the flour along with the sugar to the butter before the wet ingredients.