If you can't find Marcona almonds, use roasted, salted almonds instead. After stirring the nuts into the softened ice cream, refreeze the mixture so it can firm back up before serving.
Stir almonds into melted chocolate. Transfer almonds, a few at a time, to a parchment-lined baking sheet using a fork, letting excess chocolate drip off. Freeze for 10 minutes, then coarsely chop almonds.
Transfer ice cream to a bowl, and let stand at room temperature for 5 minutes to soften. Stir half the chocolate-covered almonds into the ice cream, and cover with plastic wrap. Freeze until firm, at least 30 minutes.
Scoop ice cream into bowls. Top with remaining almonds.
Ice cream with almonds can be frozen for up to 4 days. Remaining almonds for topping can be stored at room temperature.