For crust, in small bowl, stir together crushed cookies, graham crackers crumbs, and 1 tablespoon melted butter (mixture will be crumbly). Press onto bottom and side of a 9-inch fluted tart pan with removable bottom. Bake about 10 minutes or until crust is lightly browned. Cool on wire rack.
In blender or food processor, combine eggs, cream cheese, half-and-half, sugar, 3 tablespoons softened butter, and vanilla. Cover and blend or process until smooth.
For filling, in large bowl, combine English toffee, white chocolate, and malted milk balls. Stir in cream cheese mixture. Place crust-lined pan in shallow baking pan. Pour cream cheese mixture into crust-lined pan (pan will be full).
Bake about 30 minutes or until center appears nearly set when shaken gently. Cool in pan on a wire rack for 1 hour. Remove side of tart pan. Carefully transfer tart to serving plate. Cover and chill for 4 to 8 hours. If desired, garnish with additional chopped candy. Makes 12 servings.