Boterkoek — dense, golden Dutch butter cake

i. Origin & history

Boterkoek comes from the Netherlands, where it has been a fixture of home baking and bakery counters for generations. Its name is entirely literal: boter means butter and koek means cake, so boterkoek is simply 'butter cake'. Dutch bakeries that use real butter often label it roomboterkoek, 'cream-butter cake', to distinguish it from cheaper versions made with margarine, a distinction that matters a great deal to Dutch customers.

The cake reflects the two things the Netherlands has long had in abundance: dairy and trade. Dutch farmland made butter cheap and plentiful, and from the seventeenth century the Dutch East India Company brought sugar and spices into Amsterdam, making sweet baking part of everyday life earlier than in many parts of Europe. Boterkoek has no recorded inventor or first recipe; it is one of a family of simple koeken — along with spiced speculaas and honey cake — that grew out of that plenty.

It is not tied to a holiday. Boterkoek is a koffie cake, served when visitors arrive, at birthdays, after church on Sundays and as the afternoon treat in offices. Dutch emigrants took it to the United States, Canada, South Africa, Australia and New Zealand, and it remains a symbol of Dutch identity in those communities. The filled version with almond paste is especially associated with the festive season.

Boterkoek is sometimes confused with shortbread, and the two are close relatives. The difference is texture and fat ratio: Scottish shortbread is crisp and snaps, while boterkoek is thicker, softer and slightly fudgy in the centre, because it contains more sugar and a little egg and is deliberately baked for less time. It is also unrelated to the American 'butter cake', which is a light, risen sponge.

ii. Why boterkoek is slightly underbaked

The defining quality of a good boterkoek is its centre: dense, moist and just yielding, almost like fudge, with a crisp golden edge. That texture is the result of three things — a very high proportion of butter and sugar, no raising agent at all, and a short bake that stops before the middle is fully set.

With roughly equal weights of butter and flour, there is so much fat that very little gluten forms; the flour is coated in butter before it can hydrate. The sugar, which is almost as heavy as the flour, dissolves in the small amount of water from the butter and egg and forms a soft, syrupy matrix as it bakes. Without baking powder, nothing lifts the cake, so it stays dense.

Baking the cake through would set that sugar syrup hard and dry out the crumb, turning boterkoek into a thick shortbread. Dutch bakers take it out when the edges are golden and the top is a light gold, with the middle still soft to the touch. As it cools, the butter firms up and the centre sets into a dense, slightly chewy texture.

The finishing glaze matters too. Beaten egg brushed over the top gives the characteristic shiny, deeply golden surface, and the traditional criss-cross pattern scored into it with a fork is both decoration and a guide for cutting. Sliced almonds are often pressed into the top, and in the filled version a layer of almond paste runs through the middle.

iii. Ingredients

Makes 12 servings · scroll the side panel to adjust

• 250 g unsalted butter, softened
• 200 g caster sugar
• 8 g vanilla sugar, or 1 tsp vanilla extract
• 1 egg, beaten (half for the dough, half to glaze)
• 1 unwaxed lemon, finely grated zest (optional)
• 1 pinch salt
• 250 g plain flour
• 20 g flaked almonds, to decorate (optional)

Butter is the whole flavour of the cake, so use the best unsalted butter you can buy and let it soften fully; Dutch recipes insist on roomboter, real butter. The equal weights of butter and flour give the classic dense texture. Vanilla sugar is standard in Dutch baking and sold in small sachets; vanilla extract works equally well. Many Dutch recipes add a little lemon zest. Do not add baking powder: the cake is meant to be flat and dense. For gevulde boterkoek, the filled version, you will also need 200 g of almond paste (see Variations).

iv. Method

1. Heat the oven to 175 °C (350 °F), conventional heat. Butter a 22–24 cm round tin, ideally a shallow, loose-bottomed tart or springform tin, and line the base with baking paper.
2. Beat the butter, sugar, vanilla sugar, lemon zest and salt together with a wooden spoon or mixer on low speed until smooth and combined, about 1 minute. Do not beat it light and fluffy.
3. Add half the beaten egg and mix in; keep the rest for glazing.
4. Add the flour and mix just until a smooth, soft dough forms, without kneading.
5. Press the dough evenly into the tin with your hands or the back of a spoon, about 1.5–2 cm thick, and smooth the surface.
6. Brush the top with the remaining egg. Score a criss-cross diamond pattern across the surface with the tines of a fork, and press flaked almonds into the top if using.
7. Bake for 25–30 minutes, until the edges are golden brown and the top is a light, shiny gold. The centre should still feel soft and slightly underdone when pressed.
8. Cool completely in the tin, at least 1 hour, so the centre can set. Cut into small wedges or squares to serve.

v. Tips & common mistakes

• Take it out while it still looks underdone. This is the most important rule. The centre sets as it cools; baked until firm, the cake becomes dry and crumbly.
• Do not cream the butter and sugar to a fluff. Aerating the butter makes a lighter, cakier result. Boterkoek should be dense, so mix only until combined.
• Use soft butter, not melted. Melted butter gives a greasy cake that separates in the oven.
• Glaze thinly. Too much egg pools in the scored lines and turns them scrambled. A thin, even coat gives a shiny finish.
• Cut small pieces. Boterkoek is very rich; in the Netherlands it is served in small wedges or squares with coffee rather than in large slices.
• Let it cool fully before cutting. Warm, the soft centre will be gooey and the pieces will collapse. Cool, it cuts cleanly.

vi. Variations

Gevulde boterkoek (filled butter cake) is the most popular variation: half the dough is pressed into the tin, a layer of amandelspijs — almond paste softened with a little egg and lemon zest — is spread over it, and the rest of the dough goes on top. Gemberboterkoek adds chopped stem ginger in syrup to the dough, a favourite Dutch pairing. Some families add ground almonds or a spoonful of speculaas spice; modern bakeries sell versions with chocolate or salted caramel.

Related Dutch and Northern European bakes include the spiced speculaas biscuit, the New Year fritters oliebollen, and German Bienenstich. Mantua's sbrisolona is a crunchier Italian cousin made with the same equal-weights logic.

vii. Serving & storage

Boterkoek is served at room temperature, cut into small pieces, with coffee or tea — it is the archetypal Dutch koekje bij de koffie, the treat offered with a cup of coffee. It needs no accompaniment, though a few fresh berries help to cut the richness.

It keeps well in an airtight tin at room temperature for up to a week; the texture becomes even denser and fudgier after a day. It also freezes well: wrap the cooled cake, whole or in pieces, tightly in cling film and freeze for up to three months, then thaw at room temperature. This makes it a good cake to bake ahead for visitors.

ix. More from Austrian & German

• Speculaas — Dutch spiced biscuits
• Oliebollen — Dutch New Year fritters
• Bienenstich — German bee sting cake
• Käsekuchen — German quark cheesecake
• Shortbread — Scottish butter biscuit
• Sbrisolona — Mantuan crumbly cake