I went to college in Oregon. The little coffee shop on campus made these super yummy bars called "Buzz Bars". Before I left college, I somehow got a copy of the recipe even though I didn't work there. Here it is:
For a 9x13 pan:
Cream 2/3 cup butter with 2/3 cup brown sugar. Cream well.
Mix in 1 egg plus 1 egg yolk.
Mix in 2 2/3 cup rolled oats.
Mix in 3/8 cup light corn syrup.
Spread in a 9x13 sprayed with cooking spray. Bake at 350 degrees for 15-20 minutes (I did 18 minutes.)
The "crust" will be a little runny, but put immediately into fridge and let cool completely.
Melt 2/3 cup Skippy Natural peanut butter to spreadable consistency in a pyrex measuring cup. I microwaved it for a minute. Spread over the base and cool in the fridge.
Melt 1 cup of chocolate chips in the microwave for 1 minute. Don't overcook the chocolate chips or they'll harden up. Stir for a minute or two. If you need a little more time and the lumps aren't all getting out, microwave for 15 seconds more. When all the lumps are out, pour over the peanut butter and spread with a spatula. When cool, cut and eat them!
Today, I made a bigger pan. I have a half size bun pan (half of the commercial size cookie sheet). It has a low lip, so it works really well for this bar. At the cafe, they used full size bun pans to make them.
If you make the larger pan (18 x 13)like this one that I bought at the webstaurant store online, here are the measurements you'll need:
1 cup butter
1 cup brown sugar
4 cups uncooked rolled oats
1/2 cup corn syrup
1 cup peanut butter
1 1/3 cups chocolate chips
If you try them, I hope they turn out well for you!