Stir together flour, sugar, almonds and salt. Stir in milk, egg, 2 tablespoons melted butter and vanilla. Chill batter, covered and refrigerated, for 1 - 24 hours.
Heat pizzelle maker and lightly brush top and bottom of pizzelle molds with remaining melted butter. Pour 1 tablespoon batter into bottom of each pizzelle mold. Close cover and cook batter until golden, about 2 minutes. Work quickly to peel off 1 pizzelle and wrap around cone mold, overlapping ends, and pinching tip closed. Hold cone in place until it hardens, about 5 seconds, then slip off mold and repeat with remaining pizzelle. Repeat until 20 cones are ready.
Melt chocolate in a microwave or over a double-boiler. Work quickly to paint a thick layer of chocolate inside each pizzelle and sprinkle with almonds. Let cool and shake off any excess almonds when the chocolate has hardened.