To save anyone else the wiki trip

“Some authors consider the recipe for Aliter Dulcia (translated as ‘Another sweet dish’) included in the Apicius, a 1st-century CE Ancient Roman cuisine cookbook, “not very different” from modern French toast, although it does not involve eggs.[10][11]

In Le Viandier, culinary cookbook written around 1300, the French chef Guillaume Taillevent presented a recipe for tostées dorées[12] involving eggs and sugar.[13]”