Here are some thoughts and ideas from Anne Byrn from "The Cake Mix Doctor"
"You can get away with baking a cake from a mix, but you absolutely must make homemade frosting."
Her carrot cake suggestions:1) PINEAPPLE FILLING Cook 2 cups diced fresh pineapple and 1/2 cup sugar over low heat until tender. Add 1/4 cup pineapple juice and 2 Tbsp. cornstarch, stir, and bring to a boil. Remove from the stove immediately and cool.
2) MACADAMIA NUTSInstead of the usual walnuts or pecans, press chopped macadamia nuts onto the sides and top of the frosted cake.
3) ORANGE MARMALADE GLAZE:Heat some marmalade and brush it over the top and sides of the cake layers. Then proceed with frosting the cake.
4) GINGERAdd a pinch to the batter and 2 Tbsp. chopped crystallized ginger to the frosting
The frosting that she suggests for carrot cake:FRESH ORANGE CREAM CHEESE FROSTING1 package (8 oz.)cream cheese, at room temperature
8 Tbsp. (1 stick) butter, at room temperature
3 cups confectioners' sugar, sifted
2 Tbsp. fresh orange juice
1 Tbsp. grated orange zest (from 1 medium orange)
Place the cream cheese and butter in a large mixing bowl. Blend with an electric mixer on low speed until combined, 30 seconds. Stop the machine. Add the confectioners' sugar, a bit at a time, blending with the mixer on low speed until the sugar is well combined, 1 minute. Then add the orange juice and zest to the mixture. Increase the mixer speed to medium and beat until the frosting lightens and is fluffy, 1 minute more.
Use at once to frost the top and sides of the cake of your choice.
Source:
The Cake Mix Doctor by Anne Byrn