Green’s Dictionary of Slang

Naples biscuit and (a pair of) Macaroons n.

the penis and testicles.

1654		Mercurius Fumigosus 4 21-28 June 5: One Mr. Squirt an Apothecary, having his she-sinner following him home for some Suckitts, which he has often given her before, and begging of him a Bisket and a pair of Mackroons, which the Clown denying her, she told him she would not stir a foot without them, nor had not the power, being troubled with a standing ague in herm touch-hole; which rising he must and should allay.
1654		Mercurius Fumigosus 21 18-25 Oct. 4: The She-Piscarrions for their second Messe had Fresh-Cod and Jacks, with every Lady of the Fry a Naples Bisket and two Mackroons for digestion.