Preheat the oven to 375 degrees. Grease or foil and grease a 9x13-inch baking pan. Parchment works great too. Get out and measure all of your ingredients.
Add flour, baking powder, and salt to a mixing bowl, and whisk until combined.
Add butter and sugars to large mixing bowl and beat until light and fluffy, 2 minutes. Scrape down the sides of the bowl.
Mix eggs in butter mixture.
One egg at a time.
Add extract and mix until incorporated. Add flour mixture to butter mixture, half at a time and stir until just mixed in.
Fold in red and green sprinkles, gently.
Blend until incorporated.
Spread batter into prepared pan, as evenly as possible.
Bake in preheated oven for 25-28 minutes or until starting to turned golden brown on top and a toothpick inserted into the center comes out clean.
Remove from oven and allow to cool on wire rack.
While bars are cooling, add cream cheese and butter to a bowl or stand mixer.
Beat until well combined.
Add in powdered sugar ½ cup at a time and mix well.
Spread frosting over top of cooled bars.
Top with Oreo cookies and M&Ms.
Enjoy every bite! Serve or store in a covered container for up to 4 days.