Preheat oven to 325 degrees.
Beat eggs in large mixer bowl on high speed until foamy. Beat in flour, granulated sugar, brown sugar and vanilla. Add butter and mix well.
Stir in chocolate chips and nuts (if using). Spoon into pie shell and spread evenly.
Because I don't love nuts in things 90% of the time, I leave the nuts out of this pie. I add an extra 1/4 cup of flour to make up for some of the volume.
I like to turn my oven off after 55 minutes and then open the oven door and let the pie sit in my oven for about 10 minutes. This seems to help it not sink in the middle. Anytime I've taken it right out of the oven, it usually sinks a little in the middle, but by letting it sit in the oven and slowly begin to cool down, it helps it not sink.
You might be tempted to use milk chocolate chips, but I highly recommend using semi-sweet. This is a fairly rich and sweet pie, so using milk chocolate chips might just make it too sweet (can you believe I even just said that?!).