Line a bread pan with plastic wrap. Set aside.

Place the chocolate in a heat-proof bowl; set aside. Place the yolks with a pinch of salt in a separate heat-proof bowl; set aside.

In a medium saucepan, heat the cream over medium-low heat just until it simmers. Slowly pour the cream into the yolks, whisking constantly. Once all of the cream is incorporated, return the mixture to the saucepan and set the heat to low. Cook, stirring constantly, until the mixture is thick enough to coat the back of a wooden spoon - about 8 minutes. Do not let the mixture come to a boil. Immediately strain the cream mixture through a fine mesh sieve into the chocolate. Stir until the chocolate melts and is smooth. Refrigerate the chocolate, stirring occasionally, until it is thick - about 4 hours.

Once the chocolate is cooled and thick, spread 1 cup of the chocolate mixture onto the bottom of the prepared loaf pan. Top with one-fourth of the graham cracker crumbs. Top with a third of the remaining chocolate, followed by one-third of the bananas and strawberries. Repeat with remaining graham crackers, chocolate, bananas and strawberries until you reach the top. End with graham cracker crumbs.

Cover the cake with plastic wrap and refrigerate overnight. Uncover and turn the cake out onto a serving platter. Remove the plastic wrap from the outside of the cake. Garnish with whipped cream and additional bananas and strawberries, if desired. Cut the cake into slices to serve.