Line an 8x8-inch baking dish with foil, and spray with baking spray with flour.

For red velvet layer: In a medium saucepan, bring butter, sugar, and half-and-half to a boil over medium-high heat, stirring frequently. Cook until sugar is dissolved, about 5 minutes. Remove from heat.

Stir in white chocolate morsels, semisweet chocolate morsels, marshmallow creme, food coloring, and vanilla. Pour into prepared pan. Lift pan 1 inch above counter, and drop 3 or 4 times to release any air bubbles. Refrigerate for at least 30 minutes.

For cream cheese layer: In a microwave-safe bowl, heat white chocolate morsels on high in 30-second intervals, stirring between each, until chocolate is melted and smooth (about 1 1/2 minutes total). Let cool.

In the bowl of a stand mixer, beat cream cheese and butter at medium speed until creamy. Reduce mixer speed to low. Gradually add confectioners' sugar, beating just until combined. Increase mixer speed to medium, and beat until smooth. Add melted white chocolate, and beat until combined, about 30 seconds.

Spread cream cheese layer onto red velvet layer. Refrigerate until set about 3 hours or overnight. Remove fudge from pan, and cut into squares using a sharp knife. Garnish with pecans, if desired.