I made it with Eli, Sarah, and Abby a couple of days before Thanksgiving.
3/4 c creamy peanut butter
1/2 c unsalted butter, softened
2 c confectioner's sugar
6 ounces good-quality semisweet chocolate
36 branch-shaped pieces from mini pretzels
Stir together peanut butter and butter in a bowl with wooden spoon. Add sugar; work into a smooth dough with your hands. Refrigerate 30 minutes. (I didn't.)
Using the palms of your hands, roll dough into 1 1/2" oblong "acorns" (you should have 36), flatten 1 end of each a bit with your fingertip, and place on a waxed paper-lined rimmed baking sheet. Refrigerate 30 minutes. (I didn't do that either, but I did refrigerate them when they were done.)
Meanwhile, melt chocolate in a bowl set over a saucepan of simmering water. Working with 1 acorn at a time, insert a toothpick into rounded tip, dip flat end into chocolate, then return to baking sheet. Remove toothpick, and inset a pretzel piece into the chocolate-dipped end of each acorn. Refrigerate until chocolate is set, about 2 hours. I found that the acorn fell off the toothpick so I dipped them with my fingers.