Christmas candy making part 1 - making the cookie for the Twix style bar

This year for Christmas, I am going to make candy bars.   I am making the 4 recipes featured in this Chow post, but I am going to do it my own way.   Since I am going to try to dip these all on the same day (to save on chocolate), it's going to take some strategizing.   Here's how I am planning on doing it.  My comments are in italics.   Ahead of time, I am going to need to make make the cookie base for the Twix like candy bar first

Ingredients
1 egg
1/2 teaspoon vanilla extract
2 cups all-purpose flour
3/4 cup powdered sugar
1/2 teaspoon kosher salt
1/2 teaspoon baking powder
10 tablespoons unsalted butter (1 1/4 sticks),  cut into small pieces.  The recipe said "room temperature" but I don't know how you can cut room temperature butter into little pieces.  I am leaving mine cold.

Instructions

1. In a small bowl beat together egg and vanilla, set aside.

2. Combine flour, sugar, salt, and baking powder in the bowl of a food processor and pulse a few times to aerate and break up any lumps. Add butter and pulse until mixture looks like sand,  Add egg mixture and pulse just until dough comes together. Form into a flat, rectangular disk, wrap in plastic, and refrigerate at least 1 hour or until ready to bake.  I might make this a week ahead of time, or some weeknight when I have some spare time. 

3. Heat oven to 375°F. Place dough on a 14-inch piece of parchment paper, lightly flour, and roll into a 13-by-8-inch oval, about 1/8 inch thick. (Work quickly, because the dough will become difficult to roll as it warms up.) Transfer parchment paper with dough to a baking sheet, cover in plastic wrap, and refrigerate at least 15 minutes.

4. Trim dough to a 12-by-7-inch square and cut into 3-1/2-by-3/4-inch cookies (you need at least 24). Pierce each cookie four or five times with a chopstick or the base of a thermometer.    I am troubled by the whole idea of rolling this out into a round shape and then cutting into a rectangle?  What about patting it into the pan.  Some online research indicates it can be done either way.  But since I don't have a 12x7 pan, I guess I will roll.

5. Place on a baking sheet and cook until golden brown, about 15 minutes.

Tomorrow, I will write about making the centers.