Homemade Twix Bars

Ingredients You’ll Need

• 1 1/2 cups (190 g) all-purpose flour
• 1/3 cup (40 g) powdered sugar
• 1/4 tsp kosher salt, divided
• 3/4 cup (170 g) unsalted butter, softened, for the shortbread
• 1/2 cup (113 g) unsalted butter, for the caramel
• 1/2 cup (100 g) packed light brown sugar
• 2 tbsp light corn syrup
• 1 can (14 oz / 397 g) sweetened condensed milk
• 1 tsp vanilla extract
• 1 1/2 cups (255 g) milk chocolate chips or chopped milk chocolate
• 1/2 cup (85 g) semisweet chocolate chips
• 1 tbsp refined coconut oil or vegetable shortening

How to make homemade Twix bars

1. Step 1.

   Heat the oven to 350°F (175°C). Line an 8×8-inch metal pan with parchment, leaving an overhang on two sides.

2. Step 2.

   Whisk the flour, powdered sugar and 1/8 teaspoon of the salt in a bowl. Add the softened 3/4 cup butter and mix with a spatula or your fingertips until the dough clumps together when squeezed.

3. Step 3.

   Press the dough into an even layer in the pan, using the flat bottom of a measuring cup to smooth it. Prick all over with a fork. Bake for 22–25 minutes, until the edges are golden and the center is pale golden and firm to a light touch. Cool in the pan while you make the caramel.

4. Step 4.

   In a heavy-bottomed saucepan over medium heat, melt the 1/2 cup butter with the brown sugar, corn syrup and remaining 1/8 teaspoon salt, stirring until the sugar dissolves.

5. Step 5.

   Stir in the sweetened condensed milk. Bring to a gentle boil, then reduce the heat to medium-low. Cook for 6–8 minutes, stirring constantly and scraping the bottom and corners, until the caramel turns a light tan, thickens noticeably and a spoonful dropped on a cold plate holds a soft mound. If using a thermometer, aim for 225–230°F (107–110°C).

6. Step 6.

   Remove from the heat, stir in the vanilla and pour the caramel over the shortbread. Tilt the pan to level it. Let stand at room temperature for 20 minutes, then refrigerate for about 40 minutes, until the surface is firm to the touch and no longer tacky.

7. Step 7.

   Melt the milk chocolate, semisweet chocolate and coconut oil in a microwave-safe bowl in 20-second bursts, stirring between each, until just smooth. Spread evenly over the chilled caramel.

8. Step 8.

   Let the chocolate set at room temperature for about 1 hour, until matte and firm. Lift the slab out with the parchment, let it sit for 10 minutes if it has been refrigerated, and cut into 16 bars with a large knife warmed in hot water and wiped dry between cuts.

If this looks familiar, it should: bakers in Britain and Australia know almost the same bar as millionaire’s shortbread. The Twix version leans toward a lighter, sweeter milk chocolate top and a slightly softer caramel. The method is the same, and each layer has one thing worth getting right.

The shortbread: bake it until it is actually golden

A pale crust looks tidy but tastes floury and softens under the caramel. Bake until the edges are clearly golden and the center has taken on some color and feels firm. That extra browning is where most of the cookie’s buttery flavor comes from, and a well-baked base is what gives the bar its crisp bottom layer.

Powdered sugar keeps the shortbread tender and fine-textured, closer to the cookie in a Twix than a crunchy granulated-sugar crust. Press the dough evenly, paying attention to the corners, and prick it so it does not puff. There is no need to cool it completely before adding the caramel.

The caramel: cook to texture, not just time

Sweetened condensed milk makes this caramel forgiving, since the milk and sugar are already concentrated. But it still has to cook long enough to thicken. Undercooked caramel is the most common problem with homemade Twix bars: it looks fine in the pan and then squeezes out the sides as soon as a knife presses on the chocolate.

After the mixture comes to a boil, lower the heat and keep a silicone spatula moving across the entire bottom of the pan. Over 6 to 8 minutes it will darken from cream to a light tan, and the bubbles will become slower and thicker. The cold-plate test is the most useful cue: drop a little onto a plate from the freezer, wait 30 seconds and push it with your finger. It should hold a soft, chewy mound rather than running. A thermometer reading of 225–230°F gives the same result.

Past about 235°F, the caramel sets noticeably firmer, which some people prefer for a more candy-like bite. It also becomes harder to cut neatly through the chocolate.

Avoiding scorched caramel

Milk solids settle and burn on the bottom of a thin pan within seconds. A heavy-bottomed saucepan, medium-low heat and constant stirring prevent most problems. If you notice dark specks, do not scrape them up. Pour the caramel into the pan and leave the stuck layer behind. A small scorched patch left in the saucepan will not flavor the rest of the batch the way stirred-in flecks will.

The chocolate: why there is a little oil in it

Pure melted chocolate sets hard and brittle on a soft caramel layer. When you cut it, it cracks into shards and pushes the caramel out. A tablespoon of coconut oil or shortening softens the set just enough that the knife goes through cleanly, without making the top greasy. The semisweet chips keep the milk chocolate from tasting flat and sweet.

Melt the chocolate gently in short bursts and stop while a few unmelted bits remain; stirring finishes the job. Overheated chocolate turns thick and dull and will not spread smoothly.

Make sure the caramel is truly set before adding the chocolate. If the surface still feels tacky, warm chocolate will swirl into it instead of forming a clean top layer.

Slicing without cracking the chocolate

Let the chocolate set at room temperature if you can. Refrigerated chocolate is more likely to crack, so give a chilled slab about 10 minutes on the counter before cutting. Dip a large knife in hot water, wipe it completely dry and press straight down through the chocolate, then all the way through the crust. Clean and warm the blade before every cut. For long, Twix-style fingers, cut the slab into 4 strips and each strip into 4 pieces.

Storing and packing

Keep the bars in an airtight container with parchment between layers. At cool room temperature they keep well for about 3 days, with the caramel at its chewiest. In a warm kitchen or for longer storage, refrigerate them for up to 1 week and set them out for 15 to 20 minutes before serving, so the caramel softens and the shortbread tastes buttery again.

For a dessert table or bake sale, cut them a little smaller, into 25 squares. The layers are rich, and smaller pieces hold their shape better when people pick them up.