-
1
Preheat oven to 350F.
-
2
Butter 11x17-inch jelly roll pan.
-
3
Line with parchment.
-
4
Finely grind coconut and flour in processor.
-
5
Using electric mixer, beat yolks and 1/4 cup sugar in large bowl until pale yellow and slowly dissolving ribbon forms when beaters are lifted, about 5 minutes.
-
6
Stir in lemon peel.
-
7
Using clean dry beaters, beat whites and salt in another bowl until medium peaks form.
-
8
Gradually beat in remaining 1/4 cup sugar and beat until stiff but not dry.
-
9
Fold whites into yolk mixture in 2 additions.
-
10
Gently fold in coconut mixture.
-
11
Spread batter evenly into prepared pan.
-
12
Bake until toothpick inserted into center comes out clean, about 15 minutes.
-
13
Run small sharp knife around pan sides to loosen cake.
-
14
Slide cake on parchment onto rack; cool.
-
15
(Can be made 1 day ahead.
-
16
Return cake to pan.
-
17
Cover with plastic; store at room temperature.)
-
18
Bring first 3 ingredients to simmer in heavy medium saucepan.
-
19
Whisk yolks and flour in bowl to blend.
-
20
Gradually whisk in some of hot cream mixture.
-
21
Return mixture to saucepan and stir over medium heat until custard boils and thickens, about 2 minutes.
-
22
Pour mixture into bowl.
-
23
Cool to lukewarm.
-
24
Add butter and whisk until smooth.
-
25
Whisk in rum and coconut extract.
-
26
Cover and chill until very thick but still spreadable, about 1 hour.
-
27
Slide cake on parchment onto work surface.
-
28
Run long sharp knife between cake and parchment to loosen.
-
29
Spread filling over cake, leaving 3/4-inch border.
-
30
Starting at 1 long side, roll up cake jelly roll style.
-
31
Transfer to platter seam side down.
-
32
(Can be prepared 8 hours ahead.
-
33
Cover and refrigerate.)
-
34
Whip cream, sour cream, rum, sugar, lemon peel and vanilla in medium bowl to stiff peaks.
-
35
Spread frosting over cake.
-
36
Press coconut onto sides of cake, leaving 2-inch-wide strip without coconut down center.
-
37
Decorate center strip with lemon.
