NILLA Crust: Cream butter and sugar with electric mixer fitted with paddle attachment on low speed until smooth. Add egg; beat until combined. Scrape bottom and side of bowl. Add all-purpose flour, NILLA crumbs and salt; beat until combined.
Remove dough from bowl and flatten into 1-inch-thick rectangle. Wrap in plastic and refrigerate at least 2 hours or until firm.
Roll dough on lightly floured surface to 3/8-inch thickness. Cut out 16 (4 to 4-1/2-inch) circles using round cutter. Arrange 16 (3-inch) tart molds on parchment paper-lined sheet pans. Fit dough into molds and up the sides, without stretching. Trim dough from top of mold, if necessary. Refrigerate at least 30 min. or until firm.
Dock bottoms of tarts with fork to allow steam to escape during baking. Bake in 350°F standard oven 18 to 20 min. or until dough is light golden brown. Cool in molds on pan on wire rack. (Do not remove molds).
Custard: Meanwhile, combine milk and half the granulated sugar in saucepan. Cook on low heat, stirring until sugar is dissolved. Whisk egg, cake flour and remaining sugar in bowl. Add warm milk mixture to flour mixture; whisk until blended. Skim any foam from surface; strain mixture. Refrigerate until ready to assemble tarts.
When ready to assemble, place 3 cherries on bottom of each prepared tart shell. Top with 0.5 oz. Custard. Bake in 350°F standard oven 18 to 20 min. or until custard is set. Cool completely on pan on wire rack. Carefully remove molds just before serving.