Preheat your oven to 350°F (180°C). Spray a 9 x 5 x 3-inch loaf pan with non-stick baking spray or grease it with melted butter and a light dusting of all-purpose flour.

Use a whisk to combine the all-purpose flour, instant espresso, baking soda, and ground cinnamon in a mixing bowl. Once evenly mixed, set the bowl aside.

In a large mixing bowl, use a hand mixer to blend the melted butter, sugar, and salt together on low speed for 1 minute. After 1 minute, stop the mixer and scrape down the bowl and the beaters.

Blend the butter and sugar mixture again for 3 minutes on speed 3 (or medium speed) on your hand mixer. Stopping the mixer after the first 1 ½ minutes to scrape down the bowl and the beaters. After 3 minutes, the mixture will be pale yellow and fluffy.

Add the eggs and vanilla to the bowl with the butter-sugar mixture and blend them in on medium. Blend these for another 3 minutes, scraping down the bowl and beaters after 1 ½ minutes. The mixture will be pale yellow and thick like mayonnaise.

Blend the mashed bananas into the mixture in the bowl at low speed until they are combined, or for 1 minute. The water from the fruit will cause an imbalance in the mixture making it look curdled.

Use a sifter to sift the dry ingredients into the bowl with the rest of the ingredients. Mix the flour into the rest of the ingredients at low speed for 1 minute.

Scrape the batter into the prepared loaf pan and use the rubber spatula to smooth the surface of the batter.

Bake the banana bread for 50 minutes to 1 hour. The bread will pull away from the sides of the pan and the top of the loaf will be firm to the touch. If your bread is still gooey in the top-center of the loaf, continue baking it for 10 minutes. Cover the pan lightly with a piece of aluminum foil if it's getting too dark.

Remove the pan from the oven and allow the bread to cool inside the pan on the countertop for 10 minutes.

Remove the bread from the pan and allow it to cool for 15 minutes (or completely) on a cooling rack. Serve this recipe warm or at room temperature.