My Heart upon a little Plate — Heart-Cake

My Heart upon a little Plate 1
Her Palate to delight
A Berry or a Bun, would be,
Might it an Apricot!
(F.1039/J.1027)
[1] Heart:: heart-cake (OED 56a).
[3] Berry:: a (rabbit's) burrow. Hence, the specific name for a company of rabbits (OED n.3) Bun:: a name given sportively a. to the squirrel, b. to the rabbit (OED n.4); bun as a sort of cake hints at the answer.
[4] Apricot:: a fruit's shape similar to heart.

The use Berry, Bun, and Apricot should mean something related to the Her in line two, like a riddle in a riddle.

[1] Heart:: one's love, poetry. Plate:: a printing plate. little Plate:: Dickinson had a few poems published before 1865 when this poem was written.
[2] Her Palate:: mental taste of the literary world.
[3] Berry:: an obsolete form of bury (OED), or a sound play of it. Bun:: an obsolete form of bound (OED).
[4] Apricot:: aprick-cot; aprick as "erect, pricked or pricking up" (OED aprick); cot, "a confused entangled mass; a tangle" (OED cot n.2 2).
[3, 4] would be, might:: Dickinson's poetry would be a burial or bound to the world, a pricked confused mass of power.

QUEEN, OR HEART CAKES. 592. One pound of sifted Sugar, one pound of Butter, eight Eggs, one pound and a quarter of Flour, two ounces of Currants, and half a Nutmeg grated. Cream the Butter as at (586), and mix it well with the sugar and spice, then put in half the eggs, and beat it ten minutes, – add the remainder of the eggs, and work it ten minutes longer, – stir in the flour lightly, and the currants afterwards, – then take small tin pans of any shape (hearts the most usual), rub the inside of each with butter, fill and bake them a few minutes in a hot oven, on a sheet of matted wire, or on a baking-plate, – when done, remove them as early as possible from the pans.——The Cook's Oracle (1836)