The 20-year-old has been a permanent fixture for the Ospreys, playing in 18 of their 19 Magners League fixtures to date despite facing huge competition from British & Irish Lions tourist James Hook.
Biggar's impressive displays have seen Hook switched to midfield in a highly-publicised move that was originally heavily questioned by the Welsh media, but Holley believes that the youngster's consistent performances have proved that decision to be absolutely spot on.
"Dan has been fantastic for us this season and the players have really responded to him," said Holley, who takes the Ospreys to Dublin looking for a first win over Leinster since 2007.
"A lot was made when we picked him ahead of James Hook at fly-half last season and people questioned what we were doing.
"But Dan is a young talent who has given us real control. I feel Welsh teams need that.
"He is still learning the game but also making big steps in his career - he's done really well for us.
"I love seeing young talent coming through and it's one of the reasons why Scott Johnson and I are in the game.
"Dan is ready to challenge Stephen Jones and play for Wales. That's the next step for him.
"He has already taken over from James (Hook) and I believe we have been proven to be right to change James' position this year."
Biggar won't be the only young playmaker on display at the RDS this weekend, however.
Jonathan Sexton has been making plenty of positive headlines himself since shooting Leinster to Heineken Cup glory last year.
The 24-year-old has comfortably slotted into the sizeable boots of Argentine great Felipe Contepomi, leading Leinster to the top of the Magners League charts, as well as taking over from Ronan O'Gara as Ireland's number one No10.
Holley is just one of a number of admirers when it comes to Sexton's game and the Ospreys boss can't wait to him go head-to-head with his own protégé in the season finale.
"Dan and Jonathan both have a similar temperament and are in control of two of the biggest sides in Magners rugby now," added Holley.
"It is great and fitting that they will both be playing in Saturday's final. They have big careers ahead of them."
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