Line an 8 by 4-inch loaf pan with plastic wrap. In a small bowl, combine the egg yolks and 1/2 cup of the cream. In a large heatproof bowl, combine the chocolate, 1/2 cup of the corn syrup, and the butter. Place the bowl in a large skillet of simmering water. Cook and stir over low heat until the chocolate and butter are melted and smooth. Add the egg yolk mixture, raise the heat to medium, and cook for 3 minutes, stirring constantly. Cool to room temperature.
In a medium bowl, beat the remaining 1 1/2 cups cream, the powdered sugar, and the vanilla and almond extracts with an electric mixer until soft peaks form. Fold into the chocolate mixture until no streaks remain. Pour into the prepared loaf pan. Cover and chill overnight.
Puree the raspberries in a blender container or food processor workbowl; press through a sieve to remove the seeds. Stir in the remaining 1/4 cup of corn syrup and the liqueur. To serve, invert the terrine and cut into 5/8-inch slices. Pool some of the puree onto each dessert place. Place a slice of the terrine over the puree. Garnish with fresh raspberries and mint leaves.