Basic code: it evaluates to a template:
In[]:=
DisplayForm@FormBox[FractionBox[RowBox[{SuperscriptBox["∂",""],""}],RowBox[{RowBox[{"∂",SuperscriptBox["",""]}],"",RowBox[{"∂",SuperscriptBox["",""]}]}],MultilineFunction->None],TraditionalForm]
Out[]//DisplayForm=

∂

∂


∂


Take the template: fill in the square placeholders, one at a time:
Out[]//DisplayForm=

∂

∂


∂


3
∂

∂


∂


3
∂
(
2
x
3
y
)
∂


∂


3
∂
(
2
x
3
y
)
∂

x
∂


3
∂
(
2
x
3
y
)
∂
1
x
∂


3
∂
(
2
x
3
y
)
∂
1
x
∂

y
3
∂
(
2
x
3
y
)
∂
1
x
∂
2
y
Evaluate:
In[]:=
3
∂
(
2
x
3
y
)
∂
1
x
∂
2
y
Out[]=
12xy
Unfortunately, the generated palette does not preserve the typesetting:
In[]:=
CreatePalettePasteButtonDefer

∂

∂


∂


