Gluten Free Banana Cake with Chocolate Icing

This lovely little number is a sturdy brown butter-infused, cardamom-scented banana cake topped with a thick swipe of chocolate icing. Unlike my gluten free banana cake with cream cheese frosting, a simple yet decadent-feeling dark chocolate frosting made with bittersweet chocolate takes this cake over the top.

I love a classic banana cake served this way: The cap of chocolate elevates the humble cake into something more elegant. In this recipe, brown butter brings a deep, dark depth of flavor that's complemented by hints of vanilla and cardamom. (You'll find a bit of ginger, too, but cardamom is the overarching flavor note.)

This is not quite a one-bowl cake, but it's so simple to put together that you could whip it up in minutes on an afternoon when you have a lot of ripe bananas. The main effort comes in browning the butter, but it's so worth the little bit of extra time needed to watch the butter get deliciously crackly. For a cake that features chocolate in the cake itself, try my gluten free banana chocolate chip cake (or make a gluten free banana peanut butter cake).

Why I Love This Special Banana Cake

• Depth of flavor. The browned butter and warming spices play together to create a complex and interesting cake.
• Bananas! The natural sweetness of bananas makes this cake sweet without requiring too much added sugar (just a scant 1 cup for the whole cake). Bananas are a wonderful fruit for baking because they lend flavor, texture, and moisture.
• Whole grain flour. Naturally gluten-free, whole-grain oat flour is so perfect in this cake. Alternatively, you can use spelt flour or whole grain pastry flour by weight in this recipe if you don't need to keep gluten-free.
• Banana + chocolate = delicious. Remember those frozen bananas dipped in chocolate you loved as a kid? This cake is a grown-up version of that favorite childhood treat, but in cake form.

Ingredients You'll Need

Make sure to scroll down to my recipe card at the bottom of this post for the full ingredient amounts and instructions!

• Butter - Unsalted butter works best, but if you need to use salted butter, just reduce the amount of added salt.
• Oat flour - Learn how to make oat flour at home, or pick up a package at the store. Substitute sorghum flour or brown rice flour if you can't have oats.
• Granulated sugar - I use a scant 1 cup of sugar. You can reduce the sugar by ¼ cup if your bananas are very ripe and sweet. Alternately, try light brown sugar.
• Baking powder
• Salt - I always use fine sea salt or table salt.
• Spices - A combo of ground cardamom and ground ginger.
• Eggs - Large eggs are best.
• Vanilla - Use pure vanilla extract or vanilla bean paste.
• Greek yogurt - Full-fat or non-fat yogurt works, and you can use plain or vanilla yogurt.
• Bananas - Use very ripe bananas. You'll need about 1 ½ cups of mashed bananas.
• Frosting - Butter and semisweet chocolate chips (milk chocolate will work, too).

Tips & Some Variation Ideas

• Rest the batter - Let the batter rest for about 15 minutes before baking it. This will help create that lovely, fluffy crumb.
• Bake in an 8-inch pan - For a thicker, even fluffier cake, feel free to bake the batter in an 8-inch cake round.
• Can my bananas be too ripe? Not really! The riper bananas are, the better they become for baking, bringing loads of natural sweetness and flavor to your bakes. That being said, if you notice any mold on your bananas, toss them straight into the compost and do NOT use them!
• Add nuts - Scatter sliced, toasted (or not) almonds across the top of the icing before it fully sets.
• Skip the icing - For a super simple cake, simply sift a little powdered sugar over the top of the cake instead of the chocolate icing.
• Other spices - Play around with the spices here—swap cinnamon for the cardamom, add a pinch of nutmeg, or try adding 1 tablespoon of peeled, grated fresh ginger.

Proper Storage

• Counter - Cover the cake with foil and let it sit on the counter for up to 2 days.
• Fridge - Wrap the cake tightly and keep in the fridge for up to 5 days. Serve cold or at room temperature.
• Freezer - Place the cake (the icing will firm as it cools) in a freezer-safe bag and freeze it for up to 2 months. Thaw the cake in the freezer overnight before serving.