What does Boxing Day have to do with boxing?
Old English bacan "to bake," from Proto-Germanic *bakanan (cf. Old Norse baka, Middle Dutch backen, Old High German bahhan, German backen), from PIE *bheg- "to warm, roast, bake" (cf. Greek phogein "to roast"), from root *bhe- "to warm" (see bath). Related: Baked (Middle English had baken); baking. Baked beans attested by 1803.
"social gathering at which baked food is served," 1846, American English, from bake (v.).
The duty of preparing bread was usually, in ancient times, committed to the females or the slaves of the family (Gen. 18:6; Lev. 26:26; 1 Sam. 8:13); but at a later period we find a class of public bakers mentioned (Hos. 7:4, 6; Jer. 37:21). The bread was generally in the form of long or round cakes (Ex. 29:23; 1 Sam. 2:36), of a thinness that rendered them easily broken (Isa. 58:7; Matt. 14:19; 26:26; Acts 20:11). Common ovens were generally used; at other times a jar was half-filled with hot pebbles, and the dough was spread over them. Hence we read of "cakes baken on the coals" (1 Kings 19:6), and "baken in the oven" (Lev. 2:4). (See BREAD.)