Banana Cake II

1½ cups (210 g) flour
1 teaspoon baking powder
½ teaspoon baking soda
½ teaspoon salt
1 teaspoon ground cinnamon
¾ cup (150 g) sugar
2 tablespoons (30 g) melted butter (salted or unsalted)
1 large egg white
1 large egg, at room temperature
½ cup (125 ml) sour cream, regular or low-fat
½ teaspoon vanilla extract
1/3 cup (60 g) chocolate chips
1 cup (250 ml) banana puree, made from about 2 very ripe medium-sized bananas. Be sure to use very ripe bananas, whichever you choose: the skin should have black speckles on them and be soft to the touch.

1. Butter a 9-inch (23 cm) square pan and line the bottom with a sheet of parchment paper. Preheat the oven to 350°F (180°C). I often add a shot of hyper-strong espresso to the batter, which is positively delicious. People often raise an eyebrow when I tell them how good coffee is with bananas, but since coffee is a tropical fruit (or berry), as are bananas, the combination makes sense.
2. Sift together in a bowl the flour, baking powder, baking soda, salt, and cinnamon. Mix in the sugar.
3. In a large bowl, mix together the butter, egg white, egg, banana puree, sour cream, vanilla and espresso, if using.
4. Make a well in the center of the flour mixture and stir in the wet ingredients with a spatula until almost mixed. Add in the chocolate chips or cocoa nibs and stir until just combined, but don’t overstir: stop when any traces of flour disappear.
5. Scrape the mixture into the prepared pan and bake for 40 minutes, or until the center feels lightly-springy and just done.

Storage: This cake will keep well for 3-4 days, or can be frozen, wrapped in plastic wrap, for a few months.