Ushering little goblins from door to door in search of treats is commonplace on Halloween, but every evil genius knows the importance of whipping up a ghoulish grown-up treat too.

So slip on your lab coat, fire up the Bunsen burners and break out the beakers; it's time to channel your inner mad scientist and transform your kitchen into a libation laboratory.

Petri dishes are commonly used in laboratories for growing beastly bacteria, funky fungus and macabre mold, but takes a frenzied visionary to transmogrify a classic cocktail into a creepy gelatinous filling for a putrid petri dish.

While visually disturbing and fantastically freakish, this Halloween experiment is far from taboo and celebrates all the potent flavors of a proper Old Fashioned.

Anchored in old-school tradition, this mad scientist's version of an Old Fashioned starts with a simple syrup made from sugar, water and bitters.

I opted to use cherry bitters for an additional sweet note and my unexpected addition of herbal rosemary adds a bit of complexity to an otherwise timeless flavor profile. These elements of rosemary and cherry pair perfectly with fiery Kentucky bourbon and notes of piquant orange. Marrying the mixture with a smattering of gelatin makes this dastardly dish come together.

Even the maddest of mad scientists must follow proper lab procedures; be aware gelatin needs to “bloom” before being heated. To ensure your final petri dish product has a smooth texture, allow the unflavored gelatin to sit on the surface of the cooled simple syrup and water before heating. The cool liquid will saturate each gelatin granule forcing it to expand and ultimately dissolve evenly. Skip this step and your experiment will fail in grand fashion.

One bite of this solidified experimental delight will have your grown-up trick-or-treaters feeling the buzz of electricity coursing through their veins and laughing maniacally with horrified glee.

Cheers to a happy Halloween!

Mad Scientist's

Old Fashioned

Petri Dishes

Makes about 1 dozen 2-ounce shots.

For the cherry bitters- rosemary simple syrup:

11/2 cups sugar

1cup water

1/4 cup cherry bitters

1rosemary sprig

For the Old Fashioned gelatin:

1cup cold water

1cup cold cherry bitters-rosemary syrup

1/4 cup Maraschino cherry juice

3envelopes unflavored Knox gelatin

1cup bourbon

1/2 teaspoon grated orange

For assembly:

Orange peel

Maraschino cherries

Rosemary needles

1. To make the cherry bitters-rosemary simple syrup: Combine the sugar, water, cherry bitters and rosemary sprig in a small saucepan. Bring the mixture to a boil, stirring frequently until the sugar has dissolved. Reduce heat and allow the syrup to simmer for 6-8 minutes. Remove from heat and strain the simple syrup into a small bowl and allow to cool to room temperature before refrigerating. Syrup can be covered and refrigerated for up to 5 days.

2. To make the Old Fashioned gelatin: Combine the water, simple syrup and cherry bitters in a small saucepan. Sprinkle all three packages of gelatin evenly over the liquid and allow it to sit for 5 minutes. After the gelatin is hydrated, bring the mixture to a simmer stirring gently until gelatin is dissolved. Remove the gelatin base from the heat and stir in the bourbon and orange zest.

3. To assemble the petri dishes: Place three halved maraschino cherries, a strip of orange zest and a few rosemary needles into the bottom of the petri dishes or small shallow bowls. Pour the Old Fashioned gelatin mixture over the garnishes to the depth of about 1/4 inch. Cover the petri dishes with their glass lids (or plastic wrap if using an alternate vessel) and refrigerate 3 hours until set. Can be made 1 day ahead.