Heat oven to 350°F. Line an 8×8″ baking pan with parchment paper, leaving an overhang on two sides for easy lifting. Lightly grease parchment.
Melt the butter in a medium saucepan over medium heat, swirling occasionally until it turns lightly golden and smells nutty — about 3–4 minutes. Remove from heat.
Stir the brown sugar into the warm butter until combined. Let cool 8–10 minutes before whisking in eggs and vanilla until smooth.
Add the finely grated carrots to the batter and mix gently.
In a separate bowl, whisk together flour, salt, cinnamon, nutmeg, and ginger. Fold dry ingredients into the wet mixture just until no streaks remain — don’t overmix.
Stir in nuts, coconut
Spread batter into prepared pan and smooth the top. Bake 23–27 minutes, or until edges are set and a toothpick comes out with a few moist crumbs. Cool completely in pan on a wire rack.
Beat softened cream cheese and butter together until smooth, about 2 minutes. Add powdered sugar gradually, then vanilla (and citrus zest if using); whip until light and fluffy.
Once blondies are fully cooled, spread the frosting evenly over the top. Sprinkle with extra nuts or a touch of cinnamon if desired. Chill at least 1 hour before cutting into squares for clean edges.
Serve chilled or at room temp. Store leftovers in an airtight container in the fridge for up to 5 days.
