I played around with this, and keeping with the breakfast theme, I swapped the gin for a bottle of Earl Grey Tanqueray gin I’ve got ( because reasons, that’s why!!!), and I have to say it really works. I also swapped the syrup for vanilla syrup. The tannins of the tea really gel well with the Advocaat. Overall a really smooth and well rounded cocktail
I'm wondering if Warnink's (and by extension, advocaat for sale in the UK) is different to the advocaat here in NL because...this curdled something chronic.
I used a brand called "Twee Kippen" (two chickens). It had the thickness of a very thick custard - I had to do the ketchup bottle style of vigorously shaking to get it out of the bottle. A wide neck.
Made this with Rompone as I can't find Advocaat locally. I suppose that would make this a Mexcan Breakfast Cocktail. Maybe I'll try it with Tequila or perhaps that Mexican corn whiskey I've been wanting to find. This was quite good and is going on the favorites list.