To mix butter and sugar start by placing room temperature butter in a bowl or mixing bowl.
Then add sugar to the bowl and use an electric hand mixer or other mixer and beat the butter and sugar together on low speed until the butter has become whipped and creamy.
Then increase the speed of the mixer and continue beating the sugar and butter until the butter and sugar mixture is fluffy and light, smooth and creamy and a pale ivory color.
This process can take up to 5 to 7 minutes depending on the mixer speed.
The ideal temperature for the butter when mixing it with sugar is between 65 F to 68 F.
After the butter and sugar are mixed you can use a rubber spatula to scrape the side of the bowl once or twice while mixing.
Mixing together butter and sugar is a common first step in several baked good recipes as it incorporates air into the butter, which then helps give structure to your baked goods.
The sugar also helps to hold the air.
If you don't have a mixer you can also mash the butter and sugar gently with a fork although a mixer is much better.