HEAT oven to 350°F. Coat 12 muffin cups with no-stick cooking spray.
Place dates and baking soda in a small bowl and add boiling water. Cool to lukewarm.
Combine flour, baking powder and salt in small bowl. Beat brown sugar and butter in large bowl, with electric mixer on high, until light and fluffy. Beat in egg and vanilla until creamy. Mix in flour and date mixtures until combined. Divide batter evenly into prepared muffin cups.
Bake 17 to 19 minutes or until toothpick inserted in center comes out clean. Cool on wire rack.
For Toffee Sauce:
COOK brown sugar, whipping cream and butter in medium pan over medium heat until mixture comes to a boil. Reduce heat and simmer stirring 15 minutes or until slightly thickened. Stir in vanilla. Pour warm sauce over inverted cupcakes. Serve with whipped cream.