ripe bananas (any kind, the riper the sweeter) (300 g) • sugar, or less if your bananas are already sweet (about 3.5 oz or 100 g; I use 1/3 cup or 2.5 oz/70 g) • large egg • unsalted butter (about 2 oz or 60 g) • vegetable oil (about 2 fl oz or 60 ml) • whole milk (about 4 fl oz or 120 ml) • all-purpose flour (about 7 oz or 200 g) • baking soda (about 0.2 oz or 5 g) • salt (about 0.07 oz or 2 g) • chocolate chips, as much as you like (about 1.75–3.5 oz or 50–100 g; I just sprinkle until it looks good)