Coffee Ice Cream with Espresso Brittle Swirl

In a medium saucepan, heat the cream, milk, and crushed coffee beans to just under a boil. Remove from the heat and let stand at least 1 hour for the beans to infuse their flavor. In a medium bowl, whisk together the egg yolks and sugar. Pour the cream mixture into the egg yolks, whisking until well blended. Return this mixture to the saucepan and cook over medium heat, stirring constantly, until it thickens slightly, enough to coat the back of a wooden spoon. Strain the custard through a fine mesh sieve and chill. Freeze in an ice-cream maker following the manufacturer's instructions. When frozen but still soft, transfer the ice cream to a stainless-steel bowl and swirl in the chopped brittle with a spatula. Cover the ice cream tightly with plastic wrap and freeze. Garnish with the remaining shards of brittle, when serving, if you like.