Vase mode Mushroom Shelf

Printing the mushroom I printed with a layer height of 0.16 in vase mode. On the bottom of the print there is a 0.6 mm deep rectangle valley so for example in Cura slicer if you uncheck the Remove All Holes setting and set the number of bottom layer to 3 then the mushroom vase will have the rectangular hole you need. After finishing the bottom layers it will continue with the vase mode as normal.