Step 1: Prepare the Pickle-Brined Carrots (Optional, but Recommended). In a small bowl, combine the dill pickle brine and water. Add the reserved ½ cup of grated carrots to the brine. Let them sit at room temperature while you prepare the other components, or refrigerate for up to a few hours.

Step 2: Prepare Brined Pecans. In a small bowl, combine the other dill pickle brine and water. Add the pecans and let them sit at room temperature.

Step 3: Preheat Oven and Prepare Pans. Preheat oven to 350°F (175°C). Grease two 8-inch round cake pans. Line the pans with parchment paper circles and grease the parchment. Dust the pans with flour.

Step 4: Whisk Wet Ingredients. In a large bowl, whisk together the granulated sugar, oil, and eggs.

Step 5: Sift Dry Ingredients. In another bowl, sift together the flour, baking powder, baking soda, cinnamon, and salt.

Step 6: Combine Wet and Dry Ingredients. Add the flour mixture to the egg mixture and stir to combine.

Step 7: Add Carrots. Drain the brined carrots very well. Add both the brined and regular grated carrots to the batter and mix well.

Step 8: Divide Batter and Bake. Divide the batter between the prepared pans and bake until a toothpick inserted into the centers comes out clean, about 30 minutes.

Step 9: Cool Cake Layers. Let cool 10 minutes in the pans on a rack, then run a butter knife around the edges of the pans and remove the cakes to the rack to cool completely. Remove the parchment.

Step 10: Make the Frosting. In a large bowl, beat the butter and cream cheese with a mixer on medium speed until smooth. Add the powdered sugar, vanilla extract, and dill pickle powder, and beat until fluffy.

Step 11: Drain and Chop Pecans. Drain the pecans, and coarsely chop.

Step 12: Assemble and Frost the Cake. Place one cake layer on a platter and spread with frosting, then top with the second layer. Frost the top and sides of the cake with the remaining frosting.

Step 13: Garnish. Top the cake with the chopped pecans and dill, if desired.