Preheat oven 350 degrees. Spray a 8x8 square pan with non-stick cooking spray. Line the bottom of the pan with parchment paper. Leave an overhang of parchment paper on two sides of the pan for handles to remove the bars later on.
In a large mixing bowl, add in the butter and sugar. Mix until light and fluffy.
Add in the vanilla and flour and mix until a sandy blend forms. It form a dough ball, but if you grab up the mixture and press it together it will combine and form a ball.
Dump shortbread mixture into the prepared pan and press until the shortbread is packed into the pan and even.
Place into the oven and let it bake for 17 minutes until the edges are golden brown. Set aside and let cool while you make the cheesecake topping.
Reduce the heat of the oven to 325 degrees.
Add 1/2 a cup of strawberry jam into the mixing bowl. Microwave for 30 seconds to loosen it up.
Stir the jam to help break it up.
Add the cream cheese in with the jam. Mix with a hand mixer on medium until combined.
Add in the sugar, vanilla and egg. Mix until everything is thoroughly incorporated.
Stir in the festive sprinkles.
Spread 1/2 cup of strawberry jam on top of the partially cooked shortbread. Be sure to go to all of the edges and corners with it.
Pour the cheesecake batter on top jam and carefully spread to all the corners and edges.
Place the M&M's® on top of the cheesecake batter. They will sink in slightly.
Place into the 325 degree oven and bake for 20 - 22 minutes until the cheesecake is set.
Let the bars come to room temperature on the counter. Place into the fridge to chill overnight.