"double treat" is a correct and usable phrase in written English.
It is typically used to describe a situation or experience that is especially enjoyable or satisfying. Example: My birthday fell on a weekend this year, so my friends threw me a surprise party and then we went out for a fancy dinner. It was a double treat and definitely the best birthday I've ever had.
So maybe you give 'em a double treat that night".
We've got a double treat to kick off this week's viral video countdown.
It's a double treat: a tourist guide tells tales of Turin's confectionery tradition while a team of chefs prepare and serve arrays of blissful sweets and cakes while unveiling recipes and secrets.
There's special satisfaction in seeing an artist photograph the work space of a peer, as in Saul Leiter's portrait of a grim-looking Diane Arbus standing before her inspiration board — a double treat of authorship.
If you speak Spanish, then you're in for a double treat, as you'll be able to understand the narration.
That night became a double treat.
A novel addition to ESA processing is to include the workpiece electrically in series to the discharge circuit of the pulse generator by discharge through two inter electrode gaps using double treating electrode.
The Ni ion content released from the porous NiTi SMAs double treated by PA and O-PIII is one magnitude lower than that from the untreated porous samples.
Total RNA was extracted with Trizol (Invitrogen) and double treated with TURBO DNase (Ambion, Inc., Austin, Texas, USA) to remove genomic DNA.
Finally, multiple enzyme treatment of the donor culture is not always 100% effective in preventing invasion, and low levels of invasion can be observed even in double treated cells in invasion assays, which may decrease sensitivity in an assay depending on pretreatment of donor cultures (15, 26).
But the happy few who came out for them got the double-dip treat they anticipated.
