Line 2 baking sheets with parchment paper. Use a small cookie cutter or drinking glass to trace thirty 1 1/2 -inch circles in rows on the paper, about 1 1/2 inches apart. Flip the paper over (you'll still be able to see the marks through the paper). Finely grind the peanuts in a food processor. Add the almond flour and confectioners' sugar and pulse to make a fine powder. Sift twice through a fine sieve; discard any chunks. Beat the egg whites in a bowl with a mixer on high speed until foamy. Gradually add the granulated sugar and beat until soft peaks form. Add the vanilla and beat until stiff peaks form. Fold in half of the peanut mixture with a rubber spatula. Repeat with the remaining peanut mixture. Transfer the batter to a pastry bag with a 1/4 -inch round tip. Holding the bag perpendicular to the baking sheet, pipe mounds of batter into the traced circles on the parchment paper. Tap the baking sheets against the counter to help the batter settle. Let sit at room temperature until the tops are slightly crusty, about 15 minutes.
Meanwhile, preheat the oven to 375 degrees F. Bake the macaroons until slightly crisp, 13 to 15 minutes. Slide the parchment paper with the macaroons onto a rack to cool. Carefully remove the macaroons from the parchment paper. Spread 1 teaspoon jam on the flat side of a macaroon; top with another macaroon, flat side down. Repeat with the remaining macaroons and jam. (These are best eaten within 1 day.)
Photograph by Kana Okada