Step #1 Combine fruit & 1/4 c brown sugar, tossing to coat.
Step #2 Cover up & chill 8 hrs, stirring every once in awhile.
Step #3 Melt butter in a saucepan over med-heat/flame; add in the remaining 1/4 c brown sugar, stirring constantly, & cook, until sugar dissolves & mixture is bubbly.
Step #4 Remove from heat; slowly stir in the sour cream & vanilla.