Heat the oven to 375°F with a rack in the middle. Line an 8 1/2-by-4 1/2-inch metal loaf pan with parchment rated for this temperature, covering the bottom and sides and leaving lifting tabs. Keep the paper away from heating elements. This small loaf will sit relatively low in the pan.

Measure 240 g chickpeas and 240 g cannellini beans after rinsing and draining. Spread them on a clean kitchen towel and blot away visible surface moisture without crushing them. Transfer both beans to a food processor. Process until finely mashed, stopping to scrape the bowl so that whole beans do not remain around the blade.

Add the 4 eggs, totaling 200 g without shells. Process until the mixture becomes a thick, mostly smooth puree, scraping the bowl as needed. Small flecks of chickpea skin are fine; large bean pieces are not. The batter should fall from a spatula in heavy dollops and spread when nudged. Do not taste raw batter. Wash hands and food-contact equipment after handling raw eggs.

Scrape the batter into the lined pan and spread it evenly into the corners. Smooth the top with the spatula, then tap the pan gently on the counter to release large trapped pockets. Transfer directly to the oven; this batter requires no resting or proofing.

Bake for 60 minutes at 375°F, checking at 50 minutes. The top should look dry and lightly browned, and the center should feel set rather than ripple. Check the center with an instant-read thermometer: it must reach at least 165°F. If the center remains loose or falls below that temperature, continue baking until both conditions are met.

Cool for 60 minutes total before slicing into 8 portions. Leave the loaf in its pan for the first quarter of this period, then lift it out, peel away the parchment, and finish cooling on a wire rack. Refrigerate promptly afterward. In surroundings above 90°F, finish cooling in the refrigerator to meet the shorter food-safety deadline described under Storage and Freezing.