Desserts

Serving

Desserts Kid-friendly

Butter Tart Slice

Name: Butter Tart Slice
Total time: 50 min
Yield: 16 servings
Cuisine: Desserts
Ingredients: 1 1/2 cups all-purpose flour; 1/2 cup margarine (or butter), softened; 1/4 cup packed brown sugar; 1/2 cup butter, melted (for filling); 1 cup packed brown sugar (for filling); 2 large eggs; 1 tsp vanilla extract; 1 cup raisins or currants

A buttery shortbread base topped with a gooey brown sugar butter-tart filling, cut into bars.

50 minutes

Serves 16

Dessert

18 min prep

28 min cook

Contains common allergens

Egg Dairy Wheat

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Instructions

6 steps

1
Preheat the oven to 350°F (175°C). In a bowl, combine the flour, softened margarine, and 1/4 cup brown sugar, mixing until crumbly.
2
Press the mixture firmly and evenly into the bottom of an 8-inch square baking pan to form the base.
3
Bake the base for 10 minutes, until just set and lightly golden.
4
Meanwhile, prepare the filling: in a bowl, whisk together the melted butter, 1 cup brown sugar, eggs, and vanilla until smooth, then stir in the raisins.
5
Pour the filling over the partially baked base and return to the oven for 20 to 25 minutes, until the filling is set and golden.
6
Cool completely in the pan, then cut into squares.

Butter Tart Slice — plated and served — Serving moment. How Butter Tart Slice looks plated and ready to eat — a representative photo, not a step in the recipe.

Listahan Family Score™

76/100

Good fit for most families

Allergen-friendly 70

Kid-friendly 85

Weeknight-easy 64

Budget-friendly 86

Great leftovers 93

Pantry-friendly 66

Score reflects how well this recipe fits a typical busy household. In the app, your Family Score is personalized to your household's allergens, kids, and pantry.

Nutrition

per serving

250

Calories

2 g

Protein

34 g

Carbs

12 g

Fat

Estimated per serving. Actual values depend on the brands and portions you use.

Listahan cooking guide

Chef notes & practical guide

Technique notes, ingredient swaps, serve-alongside ideas, storage guidance, and equipment for this recipe.

Cultural context

The butter tart is one of Canada's most distinctively national desserts, with the earliest known printed recipes appearing in Ontario community cookbooks around 1900. It is believed to have evolved from Scottish and English treacle tart traditions brought by settlers, adapted with the local abundance of maple syrup and butter. The bar or 'slice' version is a practical adaptation of the classic individual tart that skips the fiddly individual pastry shells, using a press-in shortbread base instead and cutting into squares after baking.

Listahan note

This version uses a press-in shortbread base rather than rolled pastry, making it significantly more accessible without sacrificing the sticky, runny-centered filling that defines a good butter tart.

Technique cues

The filling is a cooked sugar-butter-egg custard that should remain slightly gooey in the center when cut — this is correct and traditional; overbaking firms the filling into a toffee-like set that loses the characteristic runny center that Canadians argue fiercely about.
Raisins or currants in a butter tart filling swell and absorb some of the liquid during baking, acting as moisture pockets that give each bite a burst of sweetness — rinse them in warm water and pat dry before adding to plump them.
The shortbread base should be fully baked (lightly golden, not pale) before the filling goes in — an under-baked base will become soggy under the wet filling, while a properly set base stays crisp against the gooey top.

Kitchen flow

Parallel prep: While the shortbread base pre-bakes, prepare and whisk the filling ingredients so they are ready to pour immediately when the base comes out.
Make-ahead: Butter tart slices keep well for 2-3 days and some argue they are better on day 2 when the filling has set and the flavors have melded.
Leftover move: Warm leftover squares briefly in the microwave (10-15 seconds) and serve with vanilla ice cream; the filling softens back to its just-baked gooey state.
Cleanup rhythm: The filling pan is the stickiest item; soak immediately in warm water to dissolve the sugar before it hardens into a caramel-like coating.

Ingredient brief

Role, handling, and swap guidance for each key ingredient.

1/2 cup margarine (or butter), softened

shortbread base fat

Purpose: Softened fat rubbed or beaten into the flour-sugar mixture creates a press-in shortbread crust that bakes into a crisp, tender base.

Handling: Bring to room temperature so it combines evenly with the flour without overworking the mixture.

Adaptation: All butter (rather than margarine) produces a richer, more flavorful crust with a slightly shorter crumb.

1/2 cup butter, melted (for filling)

filling richness and structure

Purpose: Melted butter is the backbone of the filling, contributing richness and helping emulsify the eggs and brown sugar into a smooth, pourable custard.

Handling: Cool slightly before whisking in the eggs so the heat does not begin to scramble them.

Adaptation: No good substitute for butter in the filling without significantly changing the character; a dairy-free version requires vegan butter.

1 cup packed brown sugar (for filling)

sweetness and caramel flavor

Purpose: Brown sugar gives the filling its characteristic deep caramel-molasses flavor; it is what distinguishes a butter tart from a plain sugar custard.

Handling: Pack firmly for an accurate measure; whisk thoroughly into the melted butter until smooth and fully dissolved.

Adaptation: Maple sugar (same quantity) creates an authentic Canadian variation with a more pronounced maple note.

2 large eggs

filling binder and set

Purpose: Eggs set the filling from liquid to a gooey, custard-like consistency during baking; the quantity here produces a soft set, not a firm one.

Handling: Beat lightly before adding to the butter-sugar mixture.

Adaptation: No reliable substitute for eggs in this custard filling.

1 cup raisins or currants

texture and sweetness pockets

Purpose: Raisins absorb butter tart filling during baking and swell into jammy pockets of sweetness that are part of the traditional character.

Handling: Rinse in warm water and pat dry before distributing over the base; soaking in rum for 10 minutes is a welcome upgrade.

Adaptation: Walnuts or pecans for a nut version; dried cranberries for a tart twist; omit entirely for a plain 'runny' butter tart slice.

Technique notes

Let the slices cool completely in the pan before cutting — the filling continues to set as it cools and cutting while hot produces messy, liquid-filled squares.
Use a sharp knife dipped in hot water and wiped dry between each cut to produce clean squares without dragging the sticky filling.
Chilling the pan in the refrigerator for 20 minutes before cutting produces the cleanest edges, especially if you are serving for company.

Ingredient swaps

Dairy-free option: Use vegan butter (same quantity) in both the base and the filling; the texture and flavor are very close to the original.
Gluten-free direction: Replace the all-purpose flour in the base with a 1:1 GF flour blend pressed in the same way; the filling is naturally gluten-free.
Maple version: Replace 2 Tbsp of the brown sugar in the filling with real maple syrup and reduce vanilla to 1/2 tsp for an authentically Canadian maple butter tart.

Serve alongside

vanilla ice cream
lightly whipped cream
a sharp cheddar cheese slice on the side (a Canadian sweet-savory tradition)
strong black tea with milk
hot black coffee
cold fresh apple cider

Serving suggestions only — check pairings for your household's allergens.

Storage & reheating

Store at room temperature in an airtight container for up to 3 days; layer with parchment to prevent sticking.
Refrigerate for up to 1 week; the filling firms considerably when cold but softens at room temperature or with brief microwaving.
Freeze individual squares wrapped in plastic for up to 2 months; thaw at room temperature for 30-45 minutes.

Equipment

9x13-inch baking pan
mixing bowl for the base
medium mixing bowl for the filling
offset spatula or back of a spoon for pressing the base evenly

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