This one beats my mom's recipe hands down. I can't even tell you where I found it but I have used it for years
- Mix butter until light and fluffy.
- Add sugar and beat again till light and fluffy.
- Sift together flour and corn starch.
- Add flour/cornstarch to butter/sugar mixture one cup at a time, making sure its well combined before adding another cup.
- Continue to combine flour into mixture until all is gone. Mix well.
- Dump dough onto a clean medium sized cookie sheet with sides.
- Spread out evenly covering the whole sheet. I use a rolling pin and roll it over the top so my finger prints aren't in the dough.
- Sprinkle 1/4 cup or less of sugar (can use colored sugar), I never measure I just sprinkle until it has a little sparkle.
- Bake at 325 for approx 20 minutes. My oven cooks really hot so you might have to add a minute or two until edges are light brown.
- When out of the oven, I cut the square or rectangles through the shortbread. When cooled I often dip one end into melted chocolate and then roll in sprinkles.