Grease a baking pan with melted butter. Don't use bottle spray oil as it does not contain much flavors.
In a mixing bowl, whisk together, eggs, egg yolks, sugar, cinnamon powder until the mixture become smoothly.
Add heavy cream and mix well.
Then add pieces of brioche & raisin, let the mixture sit to soak in the flavor for 2 hours in the mixing bowl. Stir occasionally.