A thermosetting powder coating composition comprising the following components A to D: A: one or more unsaturated resins comprising ethylenic unsaturations selected from the group consisting of polyester resins, acrylic resins, polyurethanes, epoxy resins, polyamides, polyesteramides, polycarbonates, polyureas and mixtures thereof, and B: one or more curing agents selected from the group consisting of vinyl urethanes, vinyl functionalized urethane resins and mixtures thereof, wherein at least one curing agent is curing agent A which is selected from the group consisting of i), ii) and iii): i) one or more crystalline VU-c each of which is a crystalline vinyl urethane having a melting enthalpy ΔH m ≥ 35 J/g, and one or more melting temperatures (T m) wherein any and all of the T m of the one or more crystalline VU-c are in the region of from and including 30 up to and including 80 °C, and ii) one or more crystalline VFUR-c each of which is a crystalline vinyl functionalized urethane resin having a melting enthalpy ΔH m ≥ 35 J/g, and one or more melting temperatures (T m) wherein any and all of the T m of the one or more crystalline VFUR-c are in the region of from and including 30 up to and including 80 °C, and iii) mixtures of crystalline VU-c and crystalline VFUR-c, wherein the ΔH m and T m is each measured via Differential Scanning Calorimetry according to the description, and C: one or more thermal radical initiators, wherein at least one thermal radical initiator is dilauroyl peroxide and wherein the dilauroyl peroxide is present in an amount of at least 30 and at most 190 mmol/Kg A and B, and D: one or more co-initiators selected is selected from the group consisting of onium compounds, sulpho-compounds, and mixtures thereof, and wherein the total amount of component D is at least 10 and at most 300 mmol/Kg A and B. A: one or more unsaturated resins comprising ethylenic unsaturations selected from the group consisting of polyester resins, acrylic resins, polyurethanes, epoxy resins, polyamides, polyesteramides, polycarbonates, polyureas and mixtures thereof, and B: one or more curing agents selected from the group consisting of vinyl urethanes, vinyl functionalized urethane resins and mixtures thereof, wherein at least one curing agent is curing agent A which is selected from the group consisting of i), ii) and iii): i) one or more crystalline VU-c each of which is a crystalline vinyl urethane having a melting enthalpy ΔH m ≥ 35 J/g, and one or more melting temperatures (T m) wherein any and all of the T m of the one or more crystalline VU-c are in the region of from and including 30 up to and including 80 °C, and ii) one or more crystalline VFUR-c each of which is a crystalline vinyl functionalized urethane resin having a melting enthalpy ΔH m ≥ 35 J/g, and one or more melting temperatures (T m) wherein any and all of the T m of the one or more crystalline VFUR-c are in the region of from and including 30 up to and including 80 °C, and iii) mixtures of crystalline VU-c and crystalline VFUR-c, wherein the ΔH m and T m is each measured via Differential Scanning Calorimetry according to the description, and i) one or more crystalline VU-c each of which is a crystalline vinyl urethane having a melting enthalpy ΔH m ≥ 35 J/g, and one or more melting temperatures (T m) wherein any and all of the T m of the one or more crystalline VU-c are in the region of from and including 30 up to and including 80 °C, and ii) one or more crystalline VFUR-c each of which is a crystalline vinyl functionalized urethane resin having a melting enthalpy ΔH m ≥ 35 J/g, and one or more melting temperatures (T m) wherein any and all of the T m of the one or more crystalline VFUR-c are in the region of from and including 30 up to and including 80 °C, and iii) mixtures of crystalline VU-c and crystalline VFUR-c, C: one or more thermal radical initiators, wherein at least one thermal radical initiator is dilauroyl peroxide and wherein the dilauroyl peroxide is present in an amount of at least 30 and at most 190 mmol/Kg A and B, and D: one or more co-initiators selected is selected from the group consisting of onium compounds, sulpho-compounds, and mixtures thereof, and wherein the total amount of component D is at least 10 and at most 300 mmol/Kg A and B.