Add the butter, brown sugar, and granulated sugar into a large mixing bowl (a stand mixer is best if you have one) and beat with mixer until it starts to come together, and lightens in color, 2 to 3 minutes. 1/2 cup butter, 1/2 cup brown sugar, 1/4 cup granulated sugar
Add in the egg and vanilla extract and beat until just incorporated. 1 large egg, 1 tsp vanilla extract
Dump in the flour, cornstarch, baking soda, baking powder, and salt. Mix on low speed until the wet and dry ingredients are combined. 1 3/4 cups all purpose flour, 1/2 TBS cornstarch, 1/2 tsp baking soda, 1/2 tsp baking powder, 1/2 tsp salt
Mix on low speed until the wet and dry ingredients are combined.
Add the candy corn and white chocolate into the dough (reserving about 1/4 of it to put ON TOP of the cookies after they bake). 3/4 cup candy corn , 3/4 cup chopped white chocolate
Preheat the oven to 350 degrees Fahrenheit. Line a couple baking sheets with parchment paper.
Measure out the batter to be 2 Tablespoons. Press any exposed candy corn pieces IN to the cookie dough to prevent them from melting onto the cookie sheet.
Place about 9 cookies onto the prepared cookie sheets, about 3 inches apart.
Place in the oven to bake for about 8-12 minutes, or until the cookie top is just set and bottoms are golden. (Mine usually take 10 minutes)
Remove from the oven and use a round cookie cutter (larger than each cookie) or the back of a spoon and grease with nonstick spray. Press the sides of the cookies in as needed to make them nice and round.
Top each cookie with a couple extra pieces of candy corn and white chocolate.
Allow the cookies to rest on the pan for about 5 minutes. Remove to a cooling rack to cool completely, or enjoy warm.