In a medium bowl, whisk together all dry ingredients and sprinkles. Set aside.
Preheat oven to 350 degrees and prepare a baking sheet with parchment.
In a stand mixer fitted with a paddle attachment, combine butter and sugar. Mix on high until light and fluffy.
Add eggs and vanilla extract. Mix until combined.
Add dry ingredients and mix until just combined.
Stir in lucky charms cereal.
Using a a medium ice cream scoop, scoop dough balls onto baking sheet 3 to 4 inches apart.
With the palm of your hand or the back of a large wooden spoon, flatten cookies slightly.
Bake for 10-12 minutes.
Allow cookies to cool on baking sheet.
Once cookies are cooled, move them onto a sheet of parchment paper.
Melt 4oz of white chocolate and place in a small piping bag. Cut the tip.
Drizzle white chocolate over cookies.
Add sprinkles.
Use a little bit of white chocolate to attach a lucky charms marshmallow to cookie if desired.