Chocolate Vanilla Oatmeal Stout

OK im thinking about making a chocolate vanilla oatmeal stout. How do i adjust my ibus for adding cacoa nibs to the boil? Below is the recipe im planning on using:


7 lbs 8.0 oz Pale Malt (2 Row) US (2.0 SRM) Grain 1 69.7 %
10.0 oz Roasted Barley (300.0 SRM) Grain 5 5.9 %
12.0 oz Caramel/Crystal Malt - 60L (60.0 SRM) Grain 2 7.0 %
12.0 oz Chocolate Malt (350.0 SRM) Grain 3 7.0 %
10.0 oz Barley, Flaked (1.7 SRM) Grain 4 5.9 %
8.0 oz Oats, Flaked (1.0 SRM) Grain 6 4.6 %

1.00 oz Goldings, East Kent [5.80 %] - Boil 10.0 min Hop 8 8.9 IBUs
0.35 oz Magnum [14.00 %] - Boil 60.0 min Hop 7 20.8 IBUs

4oz cacoa nibs - Boil 3.0 min
2.5 oz vanilla extra - Added during kegging

1.0 pkg Irish Ale Yeast (White Labs #WLP004) Yeast 9


Im also not sure how much vanilla to add. Suggestions?

from my research, looks like this shouldnt add much more than about 5 ibus. Any suggestion for using vanilla beans instead of extract?

https://www.homebrewtalk.com/f12/vanilla-292070/

Check out BrentR's post on beans.