I have used this one from cooks.com

6 eggs
3 1/2 c. flour
1 1/2 c. sugar
1 c. cool melted butter
4 tsp. baking powder
2 tbsp. anise extract
Preheat pizzelle griddle. Beat eggs, add sugar gradually and beat well. Add butter and anise. Sift flour and baking powder and add to creamed mixture. Dough will be very sticky. Drop by tablespoonfuls onto pizzelle griddle sprayed with Pam. Cook until steam stops and cookies are a rich golden color. Cool on wire racks and store in air-tight container. Makes five dozen.

http://www.cooks.com/rec/view/0,1918,157171-238205,00.html

oh wait, you wanted to use oil, not butter. sorry, i got this mixed.

Butter is the correct ingredient -- here is a recipe from Julia Child and Nick Malgieri:

http://www.pbs.org/food/recipes/pizzelle/

That's precisely (or almost) the recipe I use. It is from the Vitantonio Pizzelle Maker. My mother used to sell her pizzelles for many years & has made a couple of tweaks:
1, She uses margarine (vs. butter or oil). They make the crispest wafers. (But then again, the pizzelle iron is key. Vitantonio made the best irons. If you can get your hands on one of them, hang onto it!)
2. She NEVER used a non-stick pizzelle iron. They produced substandard pizzelles (even using the same recipe).
3. She used anise OIL (not extract). It imparts a richer, long-lasting flavor to the cookies. (If you think it's too strong, you may want to back off by using a 50:50 anise oil:vanilla mixture. (Pure vanilla extract, not imitation)