Having just bought some nice copper molds, I thought I'd share the results of the first bake with them :)
I'm no expert on caneles by any means, this is just what I've picked up along the way.
I've previously only made caneles using silicone molds, and got decent results. However, I wanted to try and get as perfect a canele as I could, so I invested in some (comparatively) cheap copper molds.
I had a few problems with this batch; I did not have whole milk, and I only let them rest 24h instead of the 48h my recipe requires. Also, two of my eggs had double yolks, making the total yolk count 6 instead of 4. The result turned out just fine though.
I also did not have beeswax, nor did I have any desire to mess around with it. Here is the (regular) recipe I used without my slight modifications from this time round, for regular sized (55mm) caneles:
500ml whole milk
250g caster sugar
125g AP flour
1/4 tsp salt
2 whole eggs + 2 yolks
60ml dark rum
2 tsp vanilla essence/extract
2 Days before baking:
1. Put milk and butter together in a saucepan, heat gently to ~85C
2. Take off heat and let cool to ~50C, add vanilla
3. While milk is cooling, mix together flour, sugar, and salt
4. Mix the eggs with a fork (don't beat, incorporate as little air as possible)
5. Add eggs to flour mixture and mix with a wooden spoon until it forms an evenly mixed paste
6. When milk mixture is cooled, gently pour it into the flour mixture and mix until well combined with the wooden spoon
7. Add rum
8. Cover the bowl, and refrigerate for 48h. Mix once after 24h to reincorporate the fat which will have separated and formed a layer on the top. It won't melt back in, but that is ok.
The day of baking:
1. Brush canele molds with a very thin layer of baker's grease (equal parts oil, butter, and flour) and put in the freezer for at least 15 minutes
2. Preheat the oven to 250C
3. When the oven is preheated, fill the molds, leaving about 0.5cm of space to the top
4. Place the molds on a rimmed baking sheet (one that won't warp) to catch any overflow of oil or batter, and place gently in oven
5. Immediately turn the temperature down to 230C and bake 15 mins
6. Turn once during the 15 minutes
7. Reduce oven temperature to 180C and bake for a futher 45 minutes, turning the tray 2-3 times to ensure an even bake
8. Take the caneles out when the tops are dark (not burnt), using tongs or oven mitts, turn each mold over onto a cooling rack, the canele should come out by itself if you have properly seasoned and coated the molds prior to baking
9. Let the caneles cool for around 1h before eating
-You will probably have to play around with your oven temperature and baking time, all ovens are different. My times/temperatures are given for a convection oven that runs ever so slightly hot. Hotter temperatures for shorter times will give you a darker crust and softer interior. Lower temperatures for longer times will give you a paler crust and more well-done interior.
-If mixed properly, i.e. gently and without incorporating much air, the batter will not rise much using this recipe. Mine rise at most 1cm. Don't use a whisk at any stage or, god forbid, an electric beater.
-Ensure the layer of grease is THIN. You should barely be able to see it. If the grease is too thick, you will end up with dull crusts coated with dry flour. Or if you use "white oil" you'll end up with very waxy caneles, I'm led to believe.
-You don't need beeswax to get a shiny crust or to get the caneles to release easily from the molds. No need to give yourself extra work unless you absolutely must use the authentic method for one reason or another.
-Avoid silicone molds if you care about the appearance and texture of the canele. Taste will not be affected, but silicone molds will give you a tougher, chewier crust and paler colour. That said, I've only tried 2 different silicone molds so I can't say for certain all of them are like this. You can see the rather ugly silicone mold mini-caneles behind the nice copper mold ones.