Preheat oven to 350°F. Line the bottom of a 9x5" loaf pan with parchment paper, then spray it with nonstick cooking spray (the kind with flour) or grease and flour it.
Whisk flour, baking powder, salt , cinnamon, nutmeg, and cloves in a medium bowl. Set aside.
Stir melted butter, sugar, and sour cream or Greek yogurt in a large bowl. Stir in eggs, one at a time, then stir in vanilla. Add apple cider and dry ingredients and stir just until moistened. Pour into prepared pan.
Bake for 34-40 minutes, until a toothpick comes out clean. (Mine took 39 minutes.)
While the cake is baking, make the glaze. Heat the sugar and apple cider in a small saucepan over medium heat until it boils. Boil for 1 minute, then remove from heat.
Stir together topping ingredients, sugar and cinnamon, in a small bowl.
Cool pound cake for 15 minutes in the pan. Use a knife to loosen around the edges, then carefully remove the cake and place it on a cooling rack set over a cookie sheet. Use a pastry brush to brush the apple cider glaze over the top of the cake. Immediately sprinkle with cinnamon sugar mixture. Let cool before eating.
Store loosely covered at room temperature for up to 3 days or freeze for up to 1 month. I like to slice and freeze the slices in sandwich bags.