ParametricIPOPTMinimize is a nice feature which allows you to set up an optimization with parameters and then optimize many times with different values of the parameters. Curiously, it appears to run faster than IPOPTMinimize, even with only one call, and faster than FindMinimum, when using Method -> "IPOPT"

In[9]:= AbsoluteTiming @ 
 FindMinimum[{Cos[x + y]*Sin[x - y], 0 <= x <= 3, 0 <= y <= 3, 
   0 <= x^2 + y^2 <= 4}, {{x, 1}, {y, 1}}, Method -> "IPOPT"]

Out[9]= {0.0316208, {-0.780895, {x -> 1.89249, y -> 0.646894}}}

In[3]:= Needs["IPOPTLink`"]

In[10]:= AbsoluteTiming[
 sol = IPOPTMinimize[
   Cos[x + y]*Sin[x - y], {x, y}, {1, 
    1}, {{0, 3}, {0, 3}}, {x^2 + y^2}, {{0, 4}}];
 {IPOPTMinValue[sol], IPOPTArgMin[sol]}
 ]

Out[10]= {0.0257932, {-0.780896, {1.89249, 0.646894}}}

In[11]:= AbsoluteTiming[
 pf = ParametricIPOPTMinimize[
   Cos[x + y]*Sin[x - y], {x, y}, {p1, 
    p2}, {{0, 3}, {0, 3}}, {x^2 + y^2}, {{0, 4}}, {p1, p2}];
 sol = pf[1, 1];
 {IPOPTMinValue[sol], IPOPTArgMin[sol]}
 ]

Out[11]= {0.00679227, {-0.780896, {1.89249, 0.646894}}}