I saw a card one day that had a similar format to this one with the extra panel and wanted to try to make a few of them. When I measured my card stock I just guessed so I am not sure what the directions were for the card I saw and unfortunately I didn't save it for reference.
What I did on this one was to cut a piece of Blackberry Bliss that was 5 1/2" x 6" and scored it at 4 1/4". Then I added a folded piece of Very Vanilla on top of it that was cut to 8" x 5" and scored at 4".
The top panel is Mossy Meadow and measures 4" x 3". I punched out three holes with my crop-o-dile and added some brads to connect it to the Blackberry Bliss piece before decorating the rest of the card.
The cake, candles and base are cut out with a paper snips and added to a 2 1/2" circle of Mossy Meadow card stock.
Blackberry Bliss, Tip Top Taupe, Tangerine Tango, ink
Mossy Meadow, Very Vanilla, Blackberry Bliss card stock
Farmer's Market dsp
2 1/2", 2" and 1 3/4" circle punches
5/8" striped cotton ribbon