Heat Up: Preheat your oven to 350°F (175°C). Grease your baking pan and line it with parchment paper.
Mix Dry: In a medium bowl, whisk together flour, baking powder, baking soda, salt, and all the spices (cinnamon, cardamom, ginger, cloves, allspice, pepper).
Mix Wet: In a large bowl, whisk the oil and brown sugar until combined. Add eggs one at a time, whisking well. Stir in the vanilla.
Combine: Add half the flour mixture to the wet bowl. Stir gently. Add the buttermilk. Stir gently. Add the remaining flour.
Finish Batter: Stir just until the flour streaks disappear. Do not overmix.
Bake: Pour batter into the pan. Bake for 30–35 minutes until a toothpick inserted in the center comes out clean.
Cool: Let the cake cool in the pan for 10 minutes, then transfer to a wire rack.
Glaze: Whisk glaze ingredients together. Drizzle over the completely cooled cake.