Heat the half-and-half, sugar and 1/4 teaspoon salt in a small saucepan over medium heat until the sugar is dissolved and the half-and-half is about to simmer. Meanwhile, whisk the egg yolks in a small bowl until light, fluffy and pale. Slowly add 1/2 cup of the half-and-half mixture into the egg yolks, whisking constantly to prevent scrambling the eggs. Whisk in another 1/2 cup. Return the entire mixture to the pan and continue to cook over medium-low heat, stirring constantly with a flat-bottom spoon, until the mixture thickens slightly, coating the back of the spoon, about 6 minutes. Pour the mixture into the pitcher of a blender. Add the ricotta and lemon zest. Puree on medium until smooth, about 30 seconds. Cool the mixture in the refrigerator until completely chilled, about 1 hour.
Freeze the base in an ice cream maker according to manufacturers directions. When frozen to a soft texture, add the chocolate chips and shut off the machine. Pour into an airtight container and freeze. Temper the gelato for 8 minutes before scooping.
Heat 1 tablespoon of the butter in a large skillet over medium heat. Whisk together the milk, whole eggs, vanilla, cinnamon and a pinch of salt in a medium bowl. Working one at a time, dredge 3 of the brioche slices in the batter and place directly in the skillet. Cook until golden brown and cooked through, about 3 minutes per side. Remove to a plate. Continue with the remaining bread, adding the remaining 1 tablespoon butter to the skillet.
To serve, plate a piece of toast on each plate. Top with a large scoop of gelato, sprinkle with the orange segments and drizzle with the honey and olive oil, if using.
When blending hot liquid, first let it cool for five minutes or so, then transfer it to a blender, filling only halfway. Put the lid on, leaving one corner open. Cover the lid with a kitchen towel to catch splatters, and pulse until smooth.