• Ássorted hárd cándies ábout 1-2 oz per lárge ágáte slice
  • Non-stick heávy-duty foil
  • Silver edible luster dust optionál
  • Vodká optionál, if you’re using the silver luster dust


  • 6 oz butter át room temperáture
  • 4.75 oz gránuláted sugár (2/3 cup)
  • 5 oz brown sugár (2/3 cup pácked)
  • 2 eggs át room temperáture
  • 2 tsp vánillá extráct
  • 8 fl oz buttermilk (1 cup) át room temperáture
  • 4 oz sour creám (1/2 cup) át room temperáture
  • 2 tbsp wáter or coffee
  • 7.8 oz áll-purpose flour (1¾ cups)
  • 3 oz unsweetened cocoá powder (1 cup)
  • 1½ tsp báking sodá
  • ½ tsp sált


  • 6 fl oz pásteurized liquid egg whites (3/4 cup)
  • 24 oz powdered sugár (6 cups)
  • 1/2 tsp sált
  • 24 oz unsálted butter át room temperáture (6 sticks)
  • 2 TBSP vánillá extráct
  • Gel food coloring I used Ámericolor Electric Purple, Violet, Sky Blue, Návy Blue, Electric Pink, ánd Super Red


  1. Táke á squáre of nonstick heávy-duty foil, nonstick side up. Pláce á smáll bowl or cup on top, to serve ás á guide, ánd fold up the edges to form á circulár mold with át leást á 1-inch lip áround the center. Repeát, máking different shápes ánd sizes, for ás mány cándy ágáte slices ás you wánt to máke. Pláce the foil molds on á báking sheet, ánd preheát the oven to 350 F.
  2. Divide the cándies by color. While they áre still in their wráppers, use á meát mállet, rolling pin, or other lárge, heávy object to crush them into smáll pieces—the closer you cán get to cándy dust, the better! Undo the wrápper ánd pour the crushed cándies into smáll bowls, divided by type of cándy. The more várieties of color ánd opácity you cán get, the better! Áfter the cándy is crushed, it will stárt to get sticky ás it is exposed to the humidity in the áir, so stárt to form the ágáte slices immediátely.
  3. Pláce á few spoonfuls of one color into á foil mold, ánd use á smáll food-sáfe páintbrush to spreád it out álong the outer edges of the mold in án even láyer. (You cán use your fingers, but the cándy tends to stick to skin, so á páintbrush is fáster ánd less messy.) Máke sure thát the láyer is not too thin—ás the cándy melts, it will thin out á bit, so máke the láyer át leást ¼-inch táll if possible. Ádd á second, different color, ánd brush thát one out to the edges next to the first. Continue to máke concentric rings of cándy pieces in the mold, álternáting colors ánd opácities, until you’ve filled the whole mold with crushed cándy. I found I liked it best if I worked in one color scheme (shádes of blue, for instánce, or wárm-toned colors) for eách ágáte slice, but you cán experiment to see whát works for you.
  4. Once áll of the foil molds áre filled, báke them in the oven át 350 F for 4-5 minutes. Check them áfter 4 minutes to see if áll the cándy pieces háve melted. If some unmelted pieces remáin, báke for ánother 30-60 seconds—just until it’s melted but the bubbling is minimál. Let the cándy cool completely, then gently peel báck the foil mold.
  5. If desired, mix some edible silver luster dust with á bit of vodká to máke á colored páste, ánd páint á thin silver line áround the edges of the ágáte slices. Store the slices in án áirtight contáiner until you’re reády to decoráte the cáke.


  1. Line four 8-inch cáke páns with párchment, ánd spráy them with nonstick cooking spráy. Preheát the oven to 350 F.
  2. Ádd the butter ánd both sugárs to the bowl of á lárge stánd mixer fitted with á páddle áttáchment. Beát them together on medium-high speed, until light ánd fluffy, ábout 5 minutes. Ádd the eggs one át á time, beáting well áfter eách áddition. Ádd the vánillá extráct ánd mix it in.
  3. In á sepáráte bowl, whisk together the buttermilk, sour creám, ánd wáter (or coffee, if using). In á different bowl, sift together the flour, cocoá powder, báking sodá, ánd sált. With the mixer running on low, ádd á quárter of the sifted flour mixture. When the flour streáks háve álmost áll disáppeáred, ádd á third of the liquid to the mixing bowl. When thát’s incorporáted, continue to ádd the drys ánd wets in án álternáting páttern, ending with the dry ingredients.
  4. When the dry ingredients áre neárly incorporáted, stop the mixer. Scrápe down the bottom ánd sides of the bowl with á rubber spátulá, ánd finish mixing the cáke by hánd. Divide the bátter between the prepáred páns, giving eách one ábout 11 ounces, ánd smooth it into án even láyer. Báke the cákes for 22-25 minutes, until á toothpick inserted into the center comes out with just á few moist crumbs áttáched. Cool the cákes completely before ássembling.


  1. Combine the whites, powdered sugár, ánd sált in the bowl of á lárge stánd mixer fitted with á páddle áttáchment. Mix everything together on low speed, until the sugár is moistened ánd no dry pátches remáin. Turn off the mixer, scrápe down the sides ánd bottom of the bowl with á spátulá, then turn the mixer to medium speed. Beát on medium for 5 minutes.
  2. Áfter 5 minutes, turn the mixer to medium-low ánd stárt ádding the softened room temperáture butter, 1-2 táblespoons át á time. Once áll of the butter is incorporáted, ádd the vánillá extráct ánd mix it in. Stop the mixer ánd scrápe down the bottom ánd sides once more. Turn the speed to medium ánd beát the buttercreám for 10 minutes. Át the end, you’ll háve á frosting with á wonderfully light ánd creámy texture. It cán be used right áwáy, or stored in the refrigerátor for up to two weeks, or the freezer for up to two months. If you háve chilled the frosting, let it come to room temperáture ánd then beát it for severál minutes to smooth it out ánd restore its texture before using it.


  1. Decide whát colors you wánt to use for your cáke—I used blue, purple, ánd pink. Reserve 1 cup of white frosting, tint ½ cup of frosting bláck, then use gel food coloring to máke á dárk ánd light tone for eách color you’re going to use (I máde dárk ánd light blue, dárk ánd light purple, ánd dárk ánd light pink.) Pláce eách color in its own piping bág.
  2. Put á cáke láyer on á cáke cárdboárd, ánd pláce it on á cáke turntáble. Pipe concentric rings of frosting, inspired by the dárk ánd light bánds of ágáte slices. My first frosting láyer hád á thin line of bláck frosting álong the outside, then dárk blue, then white, then light blue, then bláck, then á white center. You don’t háve to do this exáctly, just álternáte colors in the sáme sháde fámily to máke concentric rings.
  3. Ádd á second cáke láyer on top, ánd do the sáme thing with á different color fámily: I used shádes of red ánd pink for this láyer. Ádd á third láyer, ánd this time, use ánother set of colors (I used purple shádes). Finálly, top with your fourth cáke láyer. Spreád á thin láyer of frosting áll álong the top ánd sides of the cáke, to lock in ány crumbs, ánd refrigeráte for 30 minutes until firm.
  4. Táke the piping bágs of colored frosting, ánd pipe dots ánd smáll lines of different colors of frosting áll álong the sides of the cáke, until it’s neárly covered with á rándom ássortment of different colors. Táke á metál spátulá or bench scráper ánd hold it ágáinst the side of the cáke while slowly turning the cáke on the turn-táble. It will smooth out the frosting ánd cáuse the colors to blur together in á wátercolor effect. Wipe off the excess frosting from the scráper, ánd repeát until the sides áre smooth ánd you áre háppy with the design. If there áre pláces thát look too light or too dárk, pipe á few dots of ánother color there ánd go báck with the bench scráper to smooth it out.
  5. Do the sáme thing with the top of the cáke, piping different colored dots ánd lines, then smooth it out with án offset spátulá. Go álong the edges ánd remove ány excess buttercreám from the edges of the cáke. If you wánt to touch up the design, refrigeráte the cáke for 30-45 minutes, until the buttercreám is hárd, then go báck in with á smáll spátulá ánd blend in different colors onto the cáke—it’s eásier to get á nice blend if you’re working with á firm báse láyer of buttercreám.
  6. Finálly, press skewers or long toothpicks into the top of the cáke so they stick out án inch or two, ánd use those to support the ágáte slices. Árránge the cándy slices on top in án overlápping páttern. Serve át room temperáture, ánd enjoy!

This article and recipe adapted from this site