Combine powdered sugar and cornstarch in a bowl. Set aside.  (This mixture will be used to prevent stickiness)

Use parchment paper to cover the bottom of a 9×13 pan.

Sprinkle a generous amount of powder mixture to coat the bottom of pan. Set aside.

In a medium saucepan over medium low heat, combine sugar, corn syrup, and 1cup of prosecco.

Stir mixture and bring to a boil.

Place candy thermometer in the saucepan to measure the temperature.

You want the temperature to get to 240 degrees. (This may take about 6-10 minutes)

In a large mixing bowl, mix gelatin and 1cup of prosecco.

Let sit for about 5 minutes.

Once mixture in the saucepan reaches 240 degrees, slowly whisk into gelatin mixture.

Combine for about 15 minutes, until stiff peaks begin to form and mixture is lukewarm.

Add vanilla bean/extract to mixture. (This will change the color a little.)

Quickly pour marshmallow mixture into pan. Use a spatula that is covered with oil or cooking spray so that it does not stick.

Sprinkle a generous amount of powder sugar mixture to coat the top of the marshmallow.

Let marshmallow sit uncovered for 5 – 24 hours, depending on your desired stiffness.

Flip pan onto a powdered surface and remove parchment paper.

Either slice to desired size and shape or use a cookie cutter of choice.

Garnish with sprinkles if desired.