Dennis, all-butter cookies (or part margarine, part butter) will make cookies that spread more. The melting point of either butter or margarine is significantly lower than that of vegetable shortening (e.g., Crisco); so oftentimes the butter in all-butter cookies will melt before the cookies are totally set, meaning they'll flatten out and become puddle-like. Try chilling your cookie dough thoroughly before baking; or substituting shortening for part of the butter. Oh, and using a gas oven shouldn't make any difference one way or the other. Good luck — PJH@KAF

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