Preheat the oven to 350°F, and place a rack in the center. Line a 9-inch cake round with parchment or use a bundt pan..
In a large bowl, whisk together the 2 cups all-purpose flour, ¾ cup dark brown sugar, ¾ teaspoon baking soda, ½ teaspoon fine sea salt, ½ teaspoon ground cinnamon and ½ teaspoon ground cardamom.
In a separate bowl, mix together the ⅓ cup unsalted butter, 2 large eggs, 1 ½ cups mashed bananas, ¼ cup plain Greek yogurt, and 1 teaspoon pure vanilla extract. Pour the banana mixture into the flour mixture and fold with a spatula until just combined. Add the sliced almonds.
Scrape the batter into the prepared pan and bake until golden brown, about 40-50 minutes.
Transfer the pan to a wire rack to cool in the pan for 10 minutes, then turn the loaf out of the pan to cool completely.
Make Frosting:
While the cake is cooling, prepare the frosting. Melt the ½ cup semisweet chocolate chips on the stove or in the microwave; then whisk in the ¼ cup powdered sugar. Keep whisking until sugar dissolves. Add a tablespoon of warm water and whisk. Keep adding water until the frosting is smooth and not too thick. (You can decide how thick/not-thick you’d like it.)
When the cake is completely cool, drizzle the glaze on top of the cake, spreading with a spatula to cover.