Honigkuchen (Gluten-Free Honey Cake)

Cooking spray 1 regular-size orange-spice herbal tea bag 1/2 cup hot water 1 1/2 cups gluten-free flour (such as Cup4Cup Multipurpose Flour) (about 7 5/8 ounces) 1/2 cup almond flour (about 1 3/4 ounces) 1 teaspoon baking powder 1/2 teaspoon baking soda 1/2 teaspoon kosher salt 1/2 teaspoon ground cinnamon 1 cup buckwheat honey, plus more for serving 1/3 cup vegetable oil 2 large eggs, separated 1/4 cup sliced almonds Mascarpone cheese, for serving Preheat oven to 350°F. Coat a 9- x 5-inch loaf pan with cooking spray. Line bottom of pan with parchment paper; generously coat with cooking spray. Place tea bag in a small bowl; add 1/2 cup hot water, and let steep 4 minutes. Remove and discard tea bag. Let tea cool slightly, about 15 minutes. Whisk together flours, baking powder, baking soda, salt, and cinnamon in a medium bowl until combined. Whisk together honey, oil, egg yolks, and tea in a large bowl until combined. Add flour mixture to honey mixtu...