Preheat oven to 350 degrees. Toast almonds in a single layer on a baking sheet until fragrant, about 15 minutes. Let cool.
Bring sugar and 1/4 cup water to a boil in a medium saucepan, stirring until sugar dissolves. Continue to cook, without stirring, until a candy thermometer reaches 235 degrees, about 3 minutes.
Add toasted nuts. Cook, stirring constantly, until sugar begins to crystallize, about 1 minute. Stir in 1 1/4 teaspoons salt. Continue to cook, stirring, until sugar forms a thin, sandlike coating on nuts, 2 to 3 minutes more. Pour mixture out onto a parchment-lined baking sheet and let cool for 30 minutes.
Melt chocolate in a heatproof bowl set over a pan of simmering water, stirring constantly.
Working in batches, sift nuts in a colander to remove excess sugar, and transfer nuts to a large bowl. Add chocolate, stirring to coat nuts completely. Pour mixture onto a parchment-lined baking sheet and separate clusters into individual nuts using a fork. Refrigerate until firm, about 30 minutes.
Toss pralines with cocoa in a large bowl, tapping off excess. Fill 75 mini baking cups with 4 pralines each.
Pralines can be stored in an airtight container at room temperature (75 degrees or lower; refrigerate if higher) for up to 2 weeks.