How to Make It
Preheat oven to 350ºF. Grease a 9-inch square baking pan, and line with parchment paper, allowing 1 inch of paper to hang over sides of pan. Grease the parchment paper.
Spread the rice flour in an even layer on a rimmed baking sheet lined with parchment paper; transfer to oven. Bake until toasty, 8-10 minutes.
Melt the coconut oil in a medium saucepan over medium-low heat. Add the brown sugar to pan; whisk to combine. Remove from heat, allow to cool slightly.
Using a clean kitchen towel or paper towels, gently squeeze excess liquid from the grated carrots. (It’s best to do this over the kitchen sink or a large bowl to catch the liquid.) Stir the carrots and golden raisins (if using) into the brown sugar mixture. Whisk the vanilla and eggs into the brown sugar mixture, stirring until thoroughly combined; the mixture should appear shiny and emulsified. Stir in the flour, salt, cinnamon, ginger, and cardamom. Then, stir in the toasted walnut pieces.
Spread the batter evenly into prepared pan. Bake at 350ºF for 25-28 minutes, or until a toothpick inserted into center of the pan tests clean. Cool completely in pan on a wire rack. Once cool, spread Lemony Cream Cheese Frosting evenly over top and sprinkle with nuts, if desired.
To prepare the frosting, combine the cream cheese and butter in a medium bowl; beat until fluffy. Add the sugar, zest, and salt to bowl; beat until combined and smooth. Spread the mixture evenly over the cooled blondies; sprinkle with toasted coconut and walnuts, if desired. Cut into 9 even squares and serve.