repl

scala> Foo.buildBar.baz(_, _)
res0: (Int, Int) => Int = <function2>

scala> res0(1,2)
Hello!
res1: Int = 3

scala> res0(1,2)
Hello!
res2: Int = 3

scala> val x = { val z = Foo.buildBar; z.baz(_, _) }
Hello!
x: (Int, Int) => Int = <function2>

scala> x(1,2)
res3: Int = 3

scala> x(1,2)
res4: Int = 3

scala> Foo.buildBar.baz _
buildBar
Hello!
res5: (Int, Int) => Int = <function2>

scala> res5(1,2)
res6: Int = 3

weird.scala

case class Bar() {
    println("Hello!")
    def baz(x: Int, y: Int): Int = x + y
}

object Foo {
    def buildBar: Bar = Bar()
}