In a skillet, toast the pecans and coconut. Set aside.
In a saucepan, heat the condensed milk, egg yolks and butter. Stir and cook over low heat until it thickens, about 5 minutes. Stir in the pecans and vanilla. Blend well. Cool to room temperature. Garnish a sheet cake with this mixture and roll into a log.
To decorate, dust with cocoa powder or frost the log with a recipe for White Chocolate Frosting (see recipe Jam Filling and White Chocolate Frosting).