PREHEAT OVEN TO 325F DEGREES.

CARAMELIZE SUGAR IN TWO 9-INCH SQUARE PANS. ARRANGE SWEETENED MACAPUNO OVER IT. SET ASIDE.

COMBINE THE INGREDIENTS FOR THE CUSTARD IN A BOWL, STIR TO BLEND. DIVIDE THE MIXTURE INTO TWO THEN PUR INTO PANS WHILE PASSING THROUGH A STRAINER. SET ASIDE.

PREPARE CAKE: SIFT TOGETHER THE FLOUR, BAKING POWDER, SALT AND SUGAR. MAKE A WELL AT THE CENTER THEN ADD OIL, EGGYOLKS AND WATER. MIX WITH A WIRE WHISK UNTIL SMOOTH. IN A SEPARATE BOWL, BEAT EGGWHITES AND CREAM OF TARTAR UNTIL SOFT PEAKS FORM.

ADD SUGAR GRADUALLY AND CONTINUE BEATING UNTIL STIFF. FOLD INTO EGG YOLK MIXTURE. DIVIDE BATTER INTO TWO THEN POUR OVER CUSTARD. DO NOT STIR. PLACE EACH BAKING PAN IN A LARGER PAN HALF-FILLED WITH WATER.

BAKE FOR 1 HOUR OR UNTIL DONE. INVERT ON A SERVING PLATTTER.

SERVES 16-20 PER CAKE