Preheat oven to 350°F. Prepare two 9 in. x 13 in. baking pans with vegetable pan spray. Soak Bake Even Strips in cold water for 5 minutes; wrap around pan, pinning to secure.
In large bowl, beat egg whites and cream of tartar with electric mixer until they form stiff peaks. In medium bowl, stir together flour, baking soda and salt; set aside. In second large bowl, beat butter and shortening with electric mixer until creamy. Add sugar and beat until light and fluffy. Add egg yolks one at a time, beating after each addition; add vanilla. Add flour mixture alternately with buttermilk, scraping bottom and sides of bowl and mixing well after each addition. Add coconut and pecans and mix until just incorporated. Lighten batter by folding in 1/3 of egg whites; fold in remaining egg whites until no white streaks remain. Pour into prepared pan.
Bake 35-40 minutes or until toothpick inserted in center comes out clean. Cool 15 minutes. Remove from pan and cool completely on cooling grid before torting and icing.
For icing, beat cream cheese and butter in a large bowl with electric mixer until smooth. Add confectioners' sugar, 1 cup at a time, beating until incorporated. Add vanilla extract. Fill and frost cooled cake.
Serves 24-30. Makes about 7-1/2 cups batter.