• Heat oven to 350°F (176ºC) with rack set in middle position. Coat an 9-inch round cake pan with nonstick spray. Line bottom of pan with parchment paper.
• In a medium bowl, combine ¾ cup (130g) chopped dates and ½ cup (135g) root beer, microwave 1 minute. Stir then set aside.
• In a medium mixing bowl, whisk together 2 cups (250g) flour, 1½ teaspoons baking powder, 1½ teaspoons cinnamon, 1 teaspoon ginger, ¾ teaspoon nutmeg, ½ teaspoon baking soda, ½ teaspoon salt (or ¾ teaspoon if using Diamond Crystal) and ⅛ teaspoon cloves.
• In a large mixing bowl, whisk together ¾ cup (170g) dark brown sugar, ½ cup (110g) sour cream, 5 tablespoons (70g) butter, 3 tablespoons (30g) oil, 2 large eggs, and 2 teaspoons vanilla. Add in date and root beer mixture and whisk to combine.
• Using a rubber spatula, mix flour mixture into sugar mixture just until combined. Fold in 1 cup chopped walnuts.
• Scrape batter into prepared pan and smooth top. Bake until golden brown, center springs back when lightly pressed and a toothpick inserted in center comes out clean or with a few moist crumbs attached, 32–35 minutes.
• Let cake cool in pan on wire rack for 5 minutes, then turn cake out onto wire rack to cool completely, at least 1½ hours.
• Make Ahead Tip: cake can be wrapped tightly in plastic wrap and stored at room temperature for up to 3 days, though it’s best within 2 days. If you need to store it longer, pop it in the refrigerator for up to 5 days.

Root Beer Frosting

• Add remaining root beer from open can along with second can of root beer (for a total of 2⅓ cups (595g) root beer) to a saucepan. Bring to a simmer over medium heat and reduce to ⅓ cup, it should be a thin maple syrup consistency, about 30 minutes. Remove from heat and let cool until it’s just slightly warm.
• Add 6 ounces cream cheese, slightly warm root beer syrup and a pinch of salt to a medium mixing bowl, blend together using an electric mixer fitted with whisk attachment until smooth and creamy. (If you don’t have a handheld electric mixer, you can use a stand mixer or whisk by hand—just be sure to whisk vigorously so there aren’t any cream cheese lumps).
• Dollop frosting over completely cooled cake and spread into a swoopy layer over top.
• Frosted cake can be stored at room temperature for 1 day. Any longer and it should be refrigerated. Let the cake come to room temperature (at least an hour) before enjoying.