In an electric mixer, beat together butter and powdered sugar until smooth and fluffy. Mix in egg, vanilla extract and almond extract.
In a separate bowl, whisk together flour and salt. Add to butter mixture until combined. Mix in drops of green gel food coloring until the dough reaches the desired spooky shade of green. Cover and refrigerate the cookie dough for at least 30 minutes to help minimize stickiness.
Preheat oven to 325°F and line cookie sheets with parchment paper.
Working in small batches (keep the rest chilling in the fridge), measure a heaping teaspoonful of dough and roll it into a finger shape on waxed or parchment paper. Gently squeeze to form knuckles. Use a table knife or a toothpick to create finger wrinkles. Press an almond at the tip to form a fingernail bed with a fingernail. Place on prepared cookie sheet 1 inch apart.
Bake for 10 minutes or until the bottoms turn a light golden brown. Let the cookies cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely. When cool, remove the almonds and squeeze red decorating gel onto the nail bed, then replace the almond and let the "blood" ooze out around it.
Notes
Keep the Dough Cold: The dough is very sticky, so working in small batches is necessary. Continue chilling the dough you're not working with at the moment.Witch Finger Size: My #1 tip is to make the cookies super skinny, like green bean skinny. They'll puff and spread when baked, but we still want them to look like gnarly, old witch fingers.Making the Knuckles: Gently squeeze the dough to form a knuckle and use the tip of a butter knife to form the knuckle lines, varying the length. Keep everything pronounced so it will still look knobby and lined after baking. It took me multiple tries to figure this out.Bake a Sample Cookie: I baked a single cookie (several times) to get a feel for how it looked after baking and tweaked things until I was happy with the results.Allow Enough Time: Making witch finger cookies takes time and patience, so be sure you have plenty of both!Perfection is Overrated: Don't worry if they're imperfect—they'll be just fine!