Preheat oven to oven to 375*.Sift together the flour, baking powder, and salt. In a large mixer bowl, beat the eggs at high speed until lemon colored.
gradually add the sugar a tblespoon at a time, beating constantly; add the vanilla.
Reduce speed to slow and add the flour mixture to the egg mixture, beating only until blended.
add the hot water all at once and beat to a smooth batter.
Line a 15x10" jelly roll pan with wax paper and grease.
Spread the batter evenly over the pan. Bake for 12-14 minutes or until the cake is golden and springs back when you touch it lightly with your finger.
Loosen the cake carefuly from the sides of the pan with spatula. Sift powdered sugar over the cake, cover with a dish towel. Peel off the wax paper and quickly trim off the crisp edges with a sharp knife.
Beginning at short end, roll the cake and towel together into a firm roll.
cool on a rack while you prepare the filling.
in a mixer bowl, beat the cream cheese with the milk until smooth -- and fluffy.set aside.
in a saucepan, combine the sugar, cornstarch, lemon rind, and salt.
place a strainer over the pan and drain the juice from the blueberries into the mixture, setting the berries aside.
cook over medium heat until thick, stirring constantly.
Remove from the heat and stir in the butter, lemon juice and mace.
Carefully fold in the blueberries.chill.
carefully unroll the cake and spread the cream cheese mixture thinly over the entire surface.
Spread the blueberry mixture over the cream cheese to within 1/2" of the edges, and reroll the cake.
place the roll, seam side down on a rectangular tray and refrigerate until 30 minutes before serving.