Combine eggs, sugar, half and half, melted butter, baking powder, salt, and cardamom in a large bowl.

Mix well until all ingredients are incorporated.

Gradually add flour until a dough forms.

Roll out half of the dough at a time on a lightly floured surface to less than 1/8" thickness.

Cut the dough into diamond shapes, approximately 3" long.

Create diamond shapes by cutting long rows then slicing across diagonally.

Discard unused end pieces and mix back into remaining dough.

Cut a small slit lengthwise (about 1/4" long) in the center of each diamond.

Take one end of the diamond and put it through the slit, gently pulling through to create a knotted shape.

Place shaped cookies on a plate or cookie sheet.

Heat canola oil in a large, deep skillet to a depth of about 2".

Heat oil over moderately high heat until hot.

Test the oil temperature by dropping a single cookie into the oil.

The cookie should immediately bubble, float to the surface, and begin to brown on the bottom in about 20 seconds.

Flip the cookie and brown the other side.

Remove the cooked cookie to brown paper bags to drain and cool.

Cook the remaining cookies in batches of 10 or so, being careful not to overcrowd the pan.

Allow the cookies to cool completely, until crisp.

Roll the cooled cookies in powdered sugar.

Store in an airtight cookie tin.