Let ice cream sit at room temperature 10 minutes. Line loaf pan with plastic wrap and freeze until firm, at least 2 hours.
Using plastic wrap, remove ice cream from pan and cut into pieces. Sandwich between graham crackers. Freeze until ready to serve.
Microwave chocolate on 50% power in 30-second intervals, stirring in between, until melted and smooth. Drizzle over sandwiches before serving.
