Start by placing Oreos on a clean workspace. For every Oreo cookie you wish to transform into a witch hat, ensure they are intact and undamaged. Set up a piping bag fitted with a large round or star tip and fill it with vanilla frosting.

Carefully pipe a small dollop of frosting into the center of each Oreo cookie, creating a mound that will serve as the base for the chocolate kiss hat.

Sprinkle Halloween-themed sprinkles generously on top of each frosting dollop, ensuring they stick to the frosting.

Unwrap your chocolate kisses and gently press one into the center of each frosting dollop on the cookies.

Once all your Oreo Witch Hat Cookies are assembled, let them sit for about 10 minutes to allow the frosting to set slightly. Display your whimsical treats on a festive platter or cake stand.