Make the crust: Blitz pecans, almond flour, sweetener, and salt in a food processor to a fine meal. Pulse in melted butter until mixture clumps. Press firmly into a parchment-lined pan. Chill while you prep filling.
Bloom & dissolve gelatin: Sprinkle gelatin over cold water; let stand 5 min. Microwave 10 sec or warm gently until just melted — do not boil.
Whip filling: Beat cream cheese and sweetener until fluffy. Stream in heavy cream; whip to soft peaks. Blend in lime juice, zest, vanilla, and melted gelatin. Fold in diced jalapeño.
Fill & chill: Spread filling over crust; smooth top. Refrigerate at least 4 hours, overnight best, until set.
Slice & garnish: Lift parchment, cut into bars. Garnish with extra lime zest curls or a jalapeño coin.