Here's a conversion for Nestle Toll House chocolate chip cookies from drop cookies into bars. The original drop cookie recipe makes 5 dozen (dropping by rounded tablespoon). You can use this as a guide to turn most any drop cookie into bar cookies.

PAN COOKIE VARIATION: Prepare dough as above. Spread into greased 15"x10" jelly-roll pan. Bake in preheated 375ºF oven for 20 to 25 minutes or until golden brown. Cool in pan on wire rack.

Here is the link to the original cookie recipe I derived my answer from:

http://www.verybestbaking.com/recipes/specialty/nth-detail-occc.aspx

When the pan cookie variation says, "Prepare dough as above, it is talking about the recipe I provided the like for.