1. Lightly oil an 8-inch square baking pan and line bottom with waxed paper.
2. Melt 12 oz. chocolate with cream in a heatproof bowl set over a medium pan of 1 1/2 inches of simmering water, whisking until smooth (do not let bottom of bowl touch water). Remove pan from heat and whisk in vanilla and salt until smooth. Set aside.
3. Melt remaining chocolate in another bowl set over same pan of simmering water, whisking until smooth. Pour plain chocolate into prepared pan and spread to coat bottom evenly. Refrigerate for about 10 minutes to set chocolate.
4. Spread chocolate and cream mixture over set chocolate. Sprinkle evenly with almonds and gently press into chocolate. Let cool to room temperature, and then refrigerate, covered, until very firm, 3 to 4 hours, or overnight.
5. Run a thin, sharp knife around edges of pan. Turn mixture out onto a cutting board and peel away waxed paper. Turn fudge right-side up and, with a sharp knife, cut into 64 (1-inch) squares. Let stand at room temperature for a few minutes before serving.