Author/Opus: This is the 332nd puzzle from our contributing puzzlemaster Grant Fikes.
Rules: Variation of Kakuro. Some 2×2 white regions are to be shaded gray and treated as single (2×2) cells in the Double Kakuro, the position of these cells must be found while solving, and each gray cell is to be filled by a single digit which sits in multiple rows and columns. No digits can repeat within an entry, regardless of whether they are in small or large cells.
(An example Double Kakuro puzzle is linked.)
Difficulty: 2.5 stars
Time Standards (highlight to view): Grandmaster = 3:30, Master = 5:00, Expert = 10:00
Solution: PDF; a solution video is also available here.
Note: Follow this link for classic Kakuro and this link for Kakuro variations. More Kakuro puzzles can be found in Kakuro and Variations by Serkan Yürekli and in The Art of Puzzles 2.