so i have been doctoring up a boxed cake mix to make my cupcakes i add more oil and some sour cream to give it a kick to most of my cupcakes or i will add buttermilk to give it a more fluffy texture. i decided that i want to make my cupcakes from scratch as i make all of my buttercreams from scratch. i found this easy cupcake recipe and thought OK i can do this. well the cupcakes came out of the oven look like a pale vanilla flavored biscuit :( cant figure out what i did wrong 

this was the recipe and the directions

2 cups flour
1/2 teaspoon salt
2 teaspoons baking powder
1/2 cup butter, softened
3/4 cup sugar
2 eggs
1 cup milk
1 teaspoon vanilla essence (optional) (  i use Madagascar Bourbon vanilla)

preheat oven to 375f or 170c; line muffin cups with papers.
cream butter and sugar till light and fluffy. beat in eggs one at a time.
add flour (mixed with baking powder and salt) alternating with milk beat well; stir in vanilla.
divide evenly among pans and bake for 20 minutes. let cool in pans

so  i mixed the butter and sugar in my kitchen aide until it was creamy at first it was like soft crumbly texture not sure if i should have stopped mixing there then i added in the eggs flour bp and salt mixture alternating with milk until it was combined added in vanilla and then i went to go start to scoop into cupcake liners and noticed that the butter was still stuck to the bowl so i went and mixed some more ( i think i over mixed it. i poured into  liners but the batter was on the thicker side and not so runny i baked for 20 minutes i take them out and its like a pale biscuit i go to open one up and i see like bubble holes inside the cupcake and it tastes like a sweet biscuit 

can someone help me does anyone have a full prof easy cupcake batter i can make from scratch. 

It sounds to me like it was under-mixed.  When you cream your ingredients, it takes quite a bit of beating to get everything aerated.  You need to make sure that your butter is soft enough to adequately cream with the sugar.  The purpose of creaming is to incorporate air.  The sugar tears thousands of holes into the butter, and those holes are one of the things that give the cake lift when it bakes.  There should be NO visible chunks of butter after the mixture has been creamed.  It should look very light and fluffy and very pale yellow.

http://www.bbcgoodfood.com/videos/1057/creaming-butter-and-sugar

http://*********.com/quick-guide/how-to-az/mixing-method-creaming

Once you start adding the liquid and flour, that's when you don't want to over mix.  Scrape the sides well and mix it for about a minute and a half after it comes together.  I generally mix on low speed because I have a stand mixer.

You also want to make sure the ingredients are at room temperature.  I would also add about a tablespoon of vanilla instead of a teaspoon (I don't even understand how vanilla is optional).

I also recommend purchasing The Cake Bible by Rose Levy Beranbaum.  It's a great fundamental book for those starting scratch baking.

Here is the recipe that i love!  It takes a little longer to make, but worth it!

http://www.annies-eats.com/2010/01/05/vanilla-bean-cupcakes/

my problem is that the butter and sugar look grainy when it becomes creamy. i also read someplace where you cream the butter and then when its creamed you add the sugar i use the paddle attachment for the butter should i be using the whisk one instead?

You can use the paddle or whip attachment, but I prefer the paddle since that is what I always use.  If you use the whip attachment you run the risk of incorporating too much air into the final batter.  The butter should be at room temperature.  My house is pretty cool, around 68 degrees, so I leave my butter out on the counter overnight and it's perfect for baking the next day.  You need to cream past the grainy stage.  It might look both grainy and fluffy, depending on the ratio of butter to sugar.  The ratio in that recipe is close so it might still have a grainy consistency.  What kind of sugar are you using?  I use regular white granulated sugar.  They blocked that one link but it's on the Baking 9  1  1 website.  You just have to do a Google search.  Also search YouTube for some creaming videos.  You don't have to cream the butter first and then add the sugar, but that is another way of doing it if you want to.  Check out this link.  I like how she shows examples of creaming at various stages.

http://www.poiresauchocolat.net/2012/05/foundations-no3-creaming-butter-sugar.html

I cream my butter first with the wisk attachment then change to paddle and add the rest. But you need to find what works for you. some things that can effect is where u live humitity dryness altitude air condtioning and heat. It all plays a factor. You just need to keep practicing till they are perfect for you.