Cream the peanut butter and brown sugar together in a small mixing bowl. This means mix them together until it is a uniform mixture. Either by hand or with an electric mixer is okay.
Beat the egg and add it to the creamed mixture. If doing this by hand, you will have to use some muscle to really get it combined. If the mixture seems to be too runny to be cookie dough, which happens sometimes with no-stir peanut butter, add a little more brown sugar (about a Tbsp).
Add the baking soda. Again, work those arm muscles!
Roll the dough into walnut sized balls and place on a cookie sheet. Keep these cookies small. Then roll them in white sugar (optional). This will give them a pretty sparkle when baked.
You can leave them in this shape or gently flatten them using a fork to make that familiar peanut butter cookie criss-cross pattern. I like to make a little indent on the top and fill it with mini chocolate chips or a chocolate kiss.
Bake for 8-10 minutes. Don't be tempted to over bake them. They should not brown at the edges. As soon as the have puffed up and look set, take them out!
These peanut butter cookies are very delicate straight out of the oven so cool them on the pan for 10 minutes before moving them to a wire rack to finish cooling.
If you use no-stir peanut butter and the dough is not stiff like a cookie dough add another tablespoon of brown sugar. The cookies will be a little more puffy and delicate. Be sure you allow them to cool completely.