PREHEAT oven to 375° F.
COMBINE flour and baking soda in small bowl.
BEAT butter, peanut butter, granulated sugar, brown sugar and vanilla extract in large mixer bowl until creamy. Beat in egg. Gradually beat in flour mixture. Stir in Nestlé Hearts. Drop dough by rounded tablespoon onto ungreased baking sheets.
BAKE for 8 to 10 minutes or until lightly brown around edges. Cool on baking sheets for 2 minutes; remove to wire racks to cool completely.