Option 1: Simple statement
* Add clarified butter directions (for clarifying are on page 10) to the batter at the end.
* This uses parentheses to set off the extra information about where to find the directions.
Option 2: Adding a phrase
* Add clarified butter directions, for clarifying which are on page 10, to the batter at the end.
* This uses commas to set off the phrase "for clarifying which are on page 10" as a modifier.
Option 3: Using a colon
* Add clarified butter directions: for clarifying are on page 10, to the batter at the end.
* This uses a colon to introduce the clarifying information.
Option 4: Using a semicolon
* Add clarified butter directions; for clarifying are on page 10, to the batter at the end.
* This uses a semicolon to join two independent clauses.
The best option depends on the intended emphasis and clarity of the sentence.