PREHEAT oven to 350º F.
PLACE sugar, 1/2 cup water and cream of tartar in 4-cup microwave-safe glass measure.* Heat on HIGH (100%) power for 7 to 9 minutes, stopping every few minutes (Do not stir!) or until mixture turns golden brown (Sugar mixture will boil rapidly. As mixture gets hotter, check more frequently, as it will turn golden fast!). Using a potholder, quickly and carefully pour sugar mixture onto bottom of 9 x 2-inch-round cake pan. Holding the pan with potholders, care swirl around bottom and sides to coat.
COMBINE bread, evaporated milk, sweetened condensed milk, eggs, remaining 1/4 cup of water, cream cheese, vanilla extract and cinnamon in large bowl. Let soak for 5 minutes. Place mixture in blender; cover. Pulse a few times until blended.
POUR batter into prepared baking pan. Sprinkle raisins onto batter (most of the raisins will sink). Place baking pan in larger pan; fill pan with hot water to a depth of 1 inch.
BAKE for 55 to 60 minutes or until knife inserted near center comes out clean. Remove pan from water. Cool on wire rack for 1 1/2 hours. Cover; refrigerate for at least 4 hours or overnight.
TO SERVE: Let pan sit in hot water for a minute. Remove from water. Run small spatula around edge of flan. Invert serving platter over baking dish. Turn over; shake gently to release. Caramelized sugar forms sauce.
*NOTE: If a 4-cup measure is not available, sugar mixture can be prepared in large, microwave-safe glass bowl. Follow instructions as stated for glass measure; some additional time may be necessary. Watch carefully!
• Sugar mixture can also be prepared on stovetop. Place sugar, 1/2 cup water and cream of tarter in medium, heavy-duty saucepan. Heat over medium-high heat for 25 to 30 minutes (Do not stir!) or until mixture turns golden brown. As mixture gets hotter, check more frequently, as it will turn golden fast.