An interesting pattern from the 1930s.
Not in BlockBase.
I've analyzed the pattern several ways.
You could look at it as a square in a square block with curves. The blocks set in a white sash with a purple cornerstone.
It should be near #2684 New Moon
and #2685 Dolly Madison's Workbox
but it's not. Notice the extra seam in the outside curved piece.
So it might be a new number 2684.5.
Or you could look at it like this, where the purple square
is in the middle of the block.
But that has no number either.
I have another example of this design, also from the mid-20th-century.
Polka dots always a good choice.
How to draw a pattern? Here's an EQ sketch of the corners.
Or maybe like this.
Print this PDF for a 12" block.
Update: I found the pattern, one of the elusive Alice Brooks designs: