Leonardo Pacheco over on Mastodon has an epic pair of footnotes from mathematical monographs.

Peter G. Hinman, Recursion-Theoretic Hierarchies

“To anyone who has reached this note legitimately — that is, by following the proof of Theorem 4.18 — we offer our congratulations and suggest that some strong refreshment is in order. Try combining some hard-frozen strawberries, raspberries, or peaches in a blender with enough dark rum so that the result is a stiff mush (add powdered sugar if the fruit was not sweetened). Pour into a stemmed cocktail glass and relax! For an alternative, see the Notes to Barwise [1975, §II.6].”

Following the reference, he found Jon Barwise, Admissible Sets and Structures

When used in a class or seminar, section 6 should be supplemented with coffee (not decaffeinated) and a light refreshment. We suggest Heatherton Rock Cakes. (Recipe: Combine 2 cups of self-rising flour with 1 t. allspice and a pinch of salt. Use a pastry blender or two cold knives to cut in 6 T butter. Add 1/3 cup each of sugar and raisins (or other urelements). Combine this with 1 egg and enough milk to make a stiff batter (3 or 4 T milk). Divide this into 12 heaps, sprinkle with sugar, and bake at 400 °F. for 10—15 minutes. They taste better than they sound.)