I've just taken a look at the OED website.
'Macaron' isn't recognised at all, except for a historic reference from Chamber's Cyclopaedia of 1753 ("Macaron: the name of a sort of vermicelli, a paste made of flour and water, and formed into the shape of the barrel of a quill, or the guts of small fowl") and an even older reference from the Dictionary of French and English Tongues of 1611 ("Macarons: little Fritter-like Bunnes, or thicke Losenges, compounded of Sugar, Almonds, Rosewater, and Muske").