Preheat your oven to 350°F Line a 9x13-inch baking pan with parchment paper or lightly grease it.
In the bowl of a stand mixer with the paddle attachment, cream together the softened butter and granulated sugar until light and fluffy.
Add the eggs, one at a time, beating well after each addition.
Mix in the vanilla extract and almond extract, if using.
In a separate bowl, whisk together the flour, baking powder, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Spread the cookie dough evenly in the prepared baking pan.
Bake in the preheated oven for 25 minutes, or until the edges are lightly golden and a toothpick inserted into the center comes out clean.
Remove from the oven, add the marshmallows over the top until they start to melt, then press them down into the sugar cookie bars
Place the cookie bars back into the oven and cook for an additional 3 minute or until the marshmallows just start to melt. Remove from the oven and using a spatula, spread them evenly across the top of the sugar cookie bars.
While the marshmallows are still warm, drop the cookie chunks over the top evenly, pressing them into the warm marshmallows. Then sprinkle m&m's and add the sprinkles over the top, pushing down into the marshmallow topping.
Allow to cool for 15 minutes